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Trident Alternatives Review

Volume 566: debated on Wednesday 17 July 2013

Before I call the Minister responsible for the review to move the motion, I should stress that 16 Members are seeking to catch the Chair’s eye. I therefore propose that there should be a six-minute limit on Back-Bench contributions. Such a limit would of course have to be reviewed in the light of Front-Bench contributions. I feel confident, therefore, that the Minister and shadow Minister will wish considerately to tailor their contributions to facilitate the participation of their colleagues.

I beg to move,

That this House has considered the Trident Alternatives Review.

Thank you, Mr Speaker; I shall certainly do as you say. I will also tailor the number of interventions I take to meet your invocation.

Yesterday, the Prime Minister and the Deputy Prime Minister published the Trident alternatives review—the most thorough review of nuclear weapon systems and postures that the UK has undertaken for decades, and the most comprehensive analysis ever made public. For the first time in a generation—

I will make some progress before giving way.

For the first time in a generation, the Trident alternatives review shows that there are credible and viable alternatives to the United Kingdom’s current approach to nuclear deterrence. A different approach would allow the UK to contribute meaningfully to the new multilateral drive for disarmament initiated by President Obama, while maintaining our national security and our ultimate insurance policy against future threats.

I will take some interventions later, but in the light of what Mr Speaker has said, I will make some progress.

A different approach could allow long-term savings—about £4 billion over the life of the system—to be made against current plans. Let me be clear: this does not change current Government policy to maintain Britain’s nuclear deterrent and prepare for a successor system. It does mean that we can at last have an open and much more informed debate about what our nuclear weapons are for and how they should be deployed—a debate that provides our country with a chance to change course before the main-gate decision for a successor system is taken in 2016.

I am grateful to the Chief Secretary for giving way. He says this is the most comprehensive examination for many years—that is open to question—but will he explain why it considered only the four-boat and three-boat options for Trident, not the two-boat options that the Liberal Democrats plan to put to their conference as Liberal Democrat policy?

My hon. Friend will have a chance to see the proposed Liberal Democrat policy paper when it is published in a few weeks’ time. The purpose of this debate is to consider the Trident alternatives review.

On the review’s comprehensive nature, does the right hon. Gentleman not agree that a review that fails even to consider the option of not replacing Trident at all and having no nuclear submarines is ultimately flawed? Decades after the cold war and in the midst of austerity, the key question that has to be asked is whether Britain needs a nuclear submarine system that will cost us £100 billion over the next 30 years.

That is of course a legitimate point for political debate, but the purpose of the review was to consider alternative nuclear weapon systems that could act as a deterrent. The review was never designed to consider the option of unilateral disarmament, although the hon. Lady is free to argue for that.

If this was the most comprehensive examination of our nuclear weapons system in a generation, why did the right hon. Gentleman not take evidence from individuals outside government?

It was a review conducted within government, taking advice from senior officials, as with every other government review. Indeed, the right hon. Gentleman has been involved in such reviews in the past, and I am sure he knows better.

I am grateful to the right hon. Gentleman for coming to the Chamber today. He says this is the most comprehensive review we have had. That is open to question, but is he saying that after a two-year study we still do not know what the Liberal Democrat position is on this important subject?

I am here to set out the details of the review. Those are the terms of the debate today. I will set out my own views in the course of my speech, if my hon. Friend will allow me time to get on with it.

I am grateful to the Chief Secretary. I am trying to take this document seriously, but I am having some difficulty, not least because of the removal by my right hon. Friend the Deputy Prime Minister of the excellent Liberal Democrat Minister from the Ministry of Defence, which shows something of his party’s attitude towards defence. Does the Chief Secretary to the Treasury accept that his policy would destroy the submarine building industry of this country?

No, I certainly do not accept that, but I join my right hon. Friend in paying tribute to my hon. Friend the Member for North Devon (Sir Nick Harvey), who made an enormous contribution to this review.

I very much appreciate the Chief Secretary to the Treasury giving way. Further to the point on the submarine building industry, and in relation to the £4 billion saving that he has just mentioned, does he accept that chart 2 on page 42 of the document includes the platform, the missile, the infrastructure, the warhead and the policy change costs, but does not include the cost of bringing forward the next submarine project to plug the gap in the Barrow shipyard’s order book? That omission could cripple submarine building in this country for ever.

One of the review’s assumptions is that we would wish to maintain our sovereign submarine building capability. That is the policy of the Government and it sounds as though it is the hon. Gentleman’s policy, too—[Interruption.] If hon. Members will calm down for a second, I will tell them that it does include the cost of maintaining that capability. All the alternatives include the procurement of further submarines after the successor.

As the House knows, the review was commissioned by the Prime Minister and Deputy Prime Minister, initially with my hon. Friend the Member for North Devon as the Minister in charge. My hon. Friend deserves a huge share of the credit for this work. It has been taken forward under the auspices of the Cabinet Office, with a cross-government team of expert civilian and military officials. I should like to take this opportunity to thank them for their hard work.

During my visits to Aldermaston, Faslane and Coulport as part of the review, I had the privilege of meeting many of the submariners of the Royal Navy, as well as the scientists, engineers and other civilians who support them. They are some of Britain’s hidden heroes, often unsung, who operate at the limits of human understanding. Seeing them in action also gives me confidence that if the next Government were to change their mission, they would deliver it just as effectively, and in the most efficient and credible way. The review will provide the opportunity to do that.

As I said in response to an earlier intervention, it is also important to be clear what the review was not about. First, it was not about short-term savings to help to deal with the current deficit. It is possible under some of the options that savings against current plans would start to accrue from the mid-2020s, but this is not about back-filling budgets in the next Parliament. As I also said earlier, the review has not addressed the question of whether the UK should remain a nuclear weapon power, because complete unilateral disarmament is not the policy of either the Conservative party or the Liberal Democrats—or, indeed, of Labour. The review did not seek to address the question of whether we should possess nuclear weapons. However, the scale and posture of our nuclear weapon capability can change.

Many of us who believe that a continuous-at-sea nuclear deterrent is absolutely essential, and that anything else involves living in cloud cuckoo land, also believe that we should honour those who were in at the very beginning of our nuclear arms age—the British nuclear test veterans. The British Nuclear Test Veterans Association and many parliamentarians from both sides of the House have come together to campaign for recognition for the veterans. We have written to the Prime Minister and had meetings with Ministers. Will the Government look again at the campaign, because we rank very lowly on the international table of decency on this issue—

I certainly hear the point my hon. Friend is making. The veterans clearly played an important role in the development of the deterrent, and I am sure that the Under-Secretary of State for Defence, my hon. Friend the Member for Ludlow (Mr Dunne), who is going to reply to the debate, will be able to add something more on that in his comments.

The review was tasked to answer three questions. First, are there credible alternatives to submarine-based deterrence; secondly, are there credible submarine-based alternatives to the current proposal; and, thirdly, are there alternative nuclear postures that could maintain credibility? The review has been thorough, detailed, extensive and objective. The analysis looks in detail at specific combinations of platform, delivery vehicle and warhead design, but excludes technologies that could not be ready by 2035. Variants of the current successor programme are included.

As for alternative platforms, the review considered large aircraft, combat jets, surface ships and multiple types of submarine, including those with a dual role. As for alternative delivery systems, the final analysis was focused on two types of potential future cruise missile—a subsonic stealthy cruise missile and a supersonic cruise missile, each carrying one warhead. Warhead design issues were considered and were important in the review.

An assessment of our ability to deliver alternative options showed that producing the warhead and its integration into a cruise missile or bomb would be the critical challenge. The reality is that the UK nuclear warhead programme is highly optimised around producing and maintaining warheads for the Trident missile. The review found that moving towards an alternative would add technical, financial and schedule risk to the programme. Delivering a warhead for an alternative system would therefore take at least 24 years—deliverable with some risk by about 2040. The crucial point is that the review judged this warhead time scale to be longer than the Vanguard submarines can safely be operated for. There are, of course, options to bridge the gap, but when we look at the cost of alternative systems, it becomes clear that each cruise missile-based option includes an extra £10 billion on its price tag because of the need to bridge the gap.

The bottom line is this, and I quote from the review:

“The analysis has shown that there are alternatives to Trident that would enable the UK to be capable of inflicting significant damage such that most potential adversaries around the world would be deterred.”

The analysis shows that cruise missile-based options are militarily credible, but, because of the gap, my conclusion is that a replacement nuclear deterrent based on the current Trident system is the most cost-effective for the period we are considering.

I am most grateful to my right hon. Friend for giving way and I welcome his conclusion on submarines, but will he accept that continuous-at-sea deterrence is rather like pregnancy—nature admits of no middle position?

I will come to that, but I do not accept the point; that may be an accurate description of pregnancy, but not of deterrent postures.

I want to come back to the right hon. Gentleman’s analysis of the threat. Does he agree with President Obama who said in Prague that

“the threat of global nuclear war has gone down, but the risk of a nuclear attack has gone up”?

I agree with many of the things President Obama has said, including in his recent Berlin speech. I would point the hon. Lady, however, to the Government’s own threat assessment in the strategic security and defence review, which says that state-on-state nuclear attacks are a tier 2 threat. I will come to the threat analysis in a moment.

This is the nub of matter. That is just one threat assessment, but no serious conflict with which this country has been involved over decades—extending even to the second world war—has been expected. Wars are unexpected, so why does the right hon. Gentleman rest any assurance on a single threat assessment? How does he know that that threat assessment will not have to be changed in a few days’ time, let alone in 10 or 20 years?

I will address that point as I move through my speech, although I am glad to have taken my hon. Friend’s intervention. All I would say is that the degree of readiness of our conventional weapons and forces is scaled to the threats of the time, and my precise proposal is that we could adopt a similar approach here.

In assessing the contribution of President Obama to this debate, will my right hon. Friend take into account the fact that the United States is intending to reduce its fleet of submarines carrying Trident missiles from 18 to 12, and that the Berlin speech was the second time that President Obama has argued very strongly for multilateral nuclear disarmament?

I entirely agree. I applaud President Obama’s leadership of the disarmament debate. I think that the review gives the United Kingdom an opportunity to contribute further both to disarmament and to the global movement towards the de-alerting of our nuclear weapons.

No, I will not. I will give way later, but I want to make some progress first.

The review presents a much greater opportunity for change and the consideration of alternative postures, and that in turn presents the possibility of maintaining our nuclear deterrent capability with fewer submarines. This is where the real opportunity resides for making long-term savings, for recalibrating our policy to the requirements of our ages, and—as we just heard from my right hon. and learned Friend the Member for North East Fife (Sir Menzies Campbell)—for contributing to nuclear disarmament.

Analysis of the national security strategy confirms the position adopted by successive Governments that

“no state currently has both the intent and the capability to threaten the independence or integrity of the UK. But we cannot dismiss the possibility that a major direct nuclear threat to the UK might re-emerge.”

With no hostile backdrop and a surprise attack against the UK highly unlikely, the United Kingdom could adopt a number of viable and credible alternative postures while maintaining a nuclear deterrence capability that meets the needs of national security.

The review demonstrates that our current nuclear posture of continuous-at-sea deterrence is not the only one available. Let me briefly describe four of the alternative postures that were considered in the review, from highest to lowest readiness. Each of them represents a different rung on the nuclear ladder, with CASD at the top.

A posture of focused deterrence would maintain a continuous nuclear deterrent for a specific period in response to a specific threat. At all other times, the system could adopt a reduced readiness level. We considered three options for reduced readiness. A so-called sustained-deterrence posture would mean regular patrols that maintained deterrence capability, but the number of platforms could be reduced. A responsive posture would allow gaps of irregular frequency and length between deployment, so that a potential adversary could not predict when and for how long a gap in deployment might occur. A posture of preserved deterrence would hold forces at low readiness. Under preserved deterrence, no platforms would be regularly deployed, but the UK would maintain the ability to deploy if the context changed.

The review clearly demonstrates that the concept of a ladder of nuclear capability and readiness is viable and credible, and that there are a number of options for taking steps down the rungs without getting off altogether.

I will happily give way after I have made a bit more progress.

According to the review’s description of alternative postures, those options could include operating fewer Vanguard submarines, ending CASD for less frequent patrols, and unarmed patrols.

Of course, coming down the ladder depends on judgments that we make about future threats and our legal and international obligations. I should make it clear that adopting a non-continuous posture means accepting a different calculation of risk from that which existed during the cold war. However, I consider it imperative for us to update our calculation of risk. If CASD is an insurance policy, we are paying too high a premium for our needs.

I am going to make some more progress.

The 2010 national security strategy considers state-on-state nuclear war to be a second-tier threat. The argument that a current adversary would take the opportunity to target the UK during a period when no boat is covertly deployed and to launch an overwhelming nuclear strike against Britain is not supported by any analysis that I have seen.

I am going to make some progress—oh, I am sorry. I will give way to the former Defence Secretary.

What level of threat assessment would require us to go back up the ladder and reinstate CASD, and how quickly could that be done if it had been abandoned at this point?

As my right hon. Friend will know, the first question is a matter of political judgment for the Government of the day. As for the second, it would depend on which of the alternative postures was adopted. They would all be designed to allow us to surge back to the so-called focused deterrence, which would sustain a continuous posture in response to our needs.

The reality is that in the current circumstances, and for the foreseeable future, the ultimate guarantee does not need to sit on a hair trigger. We can afford to go much further in de-alerting our nuclear deterrent. The option of non-continuous deterrence does not threaten current security, and by changing postures we can reduce cost at the same time. For example, ending CASD and procuring one fewer successor submarine would make a saving of about £4 billion over the life of the system.

May I put a simple question to the right hon. Gentleman? In what circumstances would he envisage the use of nuclear weapons, and the problems that would follow as a result of their use?

The whole purpose of nuclear deterrents is to deter their use.

The judgment must be made about where on the ladder we believe that it is credible to stand, provided that the ability to scale up or down as threats change and the momentum of proliferation on the one hand and disarmament on the other shift. As a recognised nuclear weapon state under the non-proliferation treaty, we have an obligation to move towards a world in which nuclear weapons are no longer part of state security and defence postures. It is true that Britain has made significant steps since the cold war in disarmament terms. Some would argue that Britain has done its bit for disarmament and we have reached the minimum level possible. That argument has been deployed at every point at which we have scaled down over the past 20 years, but each time it has proven not to be true. The next step down the ladder is to reduce the salience of nuclear weapons in our defence policy itself, which means accepting that a cold-war-style continuous deterrent has become unnecessary.

If the right hon. Gentleman accepts that the UK will have a non-continuous deterrent, it means that there will be times when the UK does not have an active deterrent. Why then did he rule out the option, at least, of not continuing with the deterrent programme at all?

I do not accept the premise of the hon. Gentleman’s question and I have answered the substance of it in answer to an earlier intervention.

Surely we either have a full-time deterrent or we do not. If we do not have one, we might as well stand as high as we possibly can on the ladder so that our enemies can see the white flag that we will need to wave at them.

I am afraid that my hon. Friend has clearly not been listening to the analysis or read the review. Just last month, in Berlin, President Obama called for movement beyond the “cold war nuclear postures” and announced a major reduction in the US nuclear arsenal. It is my hope that in the next Parliament the UK will answer that call with a serious consideration of ending continuous nuclear deterrence.

The review is the most comprehensive study on nuclear weapon platforms and postures ever published by the UK Government. I believe that as large numbers of nuclear weapons remain and the risk of proliferation continues, it is right that the UK retains a nuclear capability for as long as the global security situation makes that necessary. But I also believe that that capability should be scaled and deployed to meet the threat we face now, and held as a contingency to deal with the threats we may face in the future. We should seek to balance the costs of this insurance policy against the other needs of defence and, indeed, other priorities across government.

The conclusion I draw from the Trident alternatives review is that although alternatives exist, there is no new system available before the lives of the current Vanguard submarines come to an end to meet those criteria. But a step down the ladder is available: ending 24-hour patrols when we do not need them and procuring fewer successor submarines, moving on from an outdated cold war concept of deterrence to one fit for the world we inhabit now. For the remainder of this Parliament the coalition Government’s policy will remain exactly as set out in the strategic defence and security review. We will maintain the deterrent as it is, and preparations for a successor system will continue. But the final main-gate decision on whether to proceed with a like-for-like replacement of Trident will be made in 2016, after the next general election. It is therefore up to the different political parties in this House to decide the positions they will take before that time. For the country, I hope that the publication of this review will mark the start of a national debate on one of the most profound questions of our time, and I commend the Trident alternatives review to the House.

I have to say at the outset that I have a little difficulty here, because the Chief Secretary to the Treasury either has a different report in front of him or he has read the report and not understood it. The Government commissioned the alternatives review into the future of UK nuclear deterrence back in 2011. It was part of the agreement in the shotgun marriage between the Conservatives and the Liberal Democrats following the 2010 general election. As he said, the Government’s stated position was to “maintain Britain’s nuclear deterrent”, but the Liberal Democrats had an opt-out in that they could be allowed to make the case for alternatives. So, more than two years later, we have finally been presented with those alternatives.

Will the Labour party confirm its admirable commitment to continuous-at-sea deterrence in any coalition negotiations? Will the hon. Gentleman say that in Labour’s view this is non-negotiable?

My position is very clear: I am working for a Labour victory at the next general election. But on the issue of continuous-at-sea deterrence, my answer is yes. Even though the report was commissioned by Her Majesty’s Government, its first line has the strange disclaimer:

“This…is not a statement of government policy.”

This must be the first time ever that the findings of a Government policy review have been abandoned at birth.

Will the hon. Gentleman explain why today’s edition of The Times carries a headline that reads “Labour could cut Trident fleet after review suggests this would save £1.7bn”?

I am not sure where that came from, first, because the figure that the hon. Lady cites is not correct—this would not be the first time that a newspaper had failed to do its sums—and, secondly, because we agree with what the Defence Secretary says. If changes in technology make the nuclear submarines more reliable, meaning that we can go down to three, we will consider that.

Many Labour Members have waited anxiously to see the report’s conclusion but, 26 months later, the review to make the case for the alternatives, which had the full weight of the Government’s resources behind it, presents us with no conclusions, makes no recommendations and does not even support adopting any of the alternatives put forward by the Chief Secretary. Only the Liberal Democrats could envisage an alternatives review that rejects all the alternatives. It is the equivalent of starting a journey to discover the ark of the covenant only to end up where we began with the conclusion that it does not exist.

The Liberal Democrats’ 2010 manifesto said:

“At a cost of £100 billion over a lifetime”


“is unaffordable, and Britain’s security would be better served by alternatives.”

If that was the case in 2010, given that those alternatives have not been identified in the review, surely it is not too much to ask that the Deputy Prime Minister and his Liberal Democrat colleagues admit that what they claimed in 2010 was wrong. One by one, each of the alternative platforms to Trident are rejected in the review. Heavy bombers, fast jets, low-orbit vehicles, land silos and maritime surface vessels are all discredited for not offering sufficient capability while costing more.

The review even dismisses the Liberal Democrats’ most favoured option of replacing Trident with nuclear-armed cruise missiles. Page 45 of the document states that cruise missiles

“offer a much reduced level of destructive and second-strike capability and an increased level of operational complexity”.

Page 6 states:

“Maintaining the same level of assurance that the UK deterrent can overcome an adversary’s defences is…likely to be harder with a cruise missile-based system.”

Page 8 points out that the cost of developing a nuclear-armed cruise missile would more than double the cost of Trident missiles and would take some 24 years. In support of that argument, the Deputy Prime Minister told Andrew Marr in 2010 that the UK

“could use Astute class submarines and use cruise missiles.”

It is true that they are alternatives but, as the report says, they are not only very expensive, but not very good.

The review totally discredits the Liberal Democrats’ previous policy decisions. In fact, some of the more ludicrous suggestions were not considered in the report because exploring them was deemed to be a waste of civil service time and energy. Page 16 dismisses some of those more wacky ideas, such as using helicopters, unmanned air vehicles or space-based platforms. Hand-held devices on the ground were also excluded

“as they would not meet several constraints, including in particular credibility and absolute range.”

The report is therefore credible, as even the most far-fetched suggestions put forward in the outer reaches of the Liberal Democrat world have been addressed.

The hon. Gentleman is right that not all parties have been entirely consistent on this matter, but may I remind him that, prior to the 1992 election, the Labour party refused to commit to a fourth submarine, but suggested that one way of maintaining employment at Barrow-in-Furness would be to turn the submarine into an underwater oil carrier?

I had not heard that one. I thought the Liberal Democrats might come forward with a proposal to turn one of the submarines into an underwater famine relief vessel, or some such nonsense.

The right hon. and learned Member for North East Fife (Sir Menzies Campbell) has a point, but does it not prove that we have learnt from our past mistakes and clearly the Liberal Democrats have not?

I could not have put it better myself. I will move on to discuss my hon. Friend’s constituency in a minute.

I think that the right hon. and learned Gentleman has had enough time, and the time is limited.

There was another option that was deemed unworthy of examination by what is otherwise a thorough and forensic document: sending two unarmed submarines out on patrol with the intention of stepping up our posture in a time of crisis. That is the policy the Chief Secretary has just proposed.

I read that report in The Times, and it seems to me that what was being said was that the Labour party is committed to continuous-at-sea deterrence and the only question is whether it can do it with three submarines or whether it would have to do it with four. The one thing that is absolutely certain from the report is that it cannot be done with two, yet the Chief Secretary’s position is that if a crisis arose they would step up their performance. How could we build a third or fourth extra submarine in time to step up our performance if a crisis arose?

I know that the hon. Gentleman has studied this subject thoroughly and is an expert. I totally agree with him. As I said, the Chief Secretary clearly has not read his own report because, as the hon. Gentleman rightly says, it outlines the problem with having only two submarines.

The Liberal Democrats briefed the newspapers earlier this week that the two-boat option would be a way forward, and the Chief Secretary has just re-outlined that ludicrous policy. My right hon. Friend the Member for East Renfrewshire (Mr Murphy) hit the nail on the head yesterday when he said that it was a little like installing a very expensive burglar alarm on one’s house with no batteries and putting up a sign saying, “Burglars, come in.” The only difference is that this would be a multi-billion pound deterrent that would not deter.

I am sure that the hon. Gentleman, and indeed the Government, would pride themselves on adhering to international law, so can he explain how maintaining an arsenal of nuclear weapons for decades to come is in line with the UK’s obligation under the nuclear non-proliferation treaty, which is

“to pursue negotiations in good faith on… nuclear disarmament”?

It is very consistent, and I am very proud of the Labour Government’s record on reducing our nuclear stockpiles, as we reduced the number of WE177 bombs and the number of warheads. I disagree with the hon. Lady’s position, but I respect the fact that she has one, which is a lot more honest that the Liberal Democrats.

However, credit should be given where credit is due. I think that the Chief Secretary should get some credit, because he managed to do something yesterday that I thought was remarkable, although I am sad that it was not reported more in this morning’s newspapers: he got the Prime Minister and Len McCluskey, the general secretary of Unite, to agree with one another, on this occasion on the Liberal Democrat proposals. That was some feat. If he is able to bring two individuals with such diametrically opposed views together, clearly he should turn his attention to the middle east peace process. Quite rightly, Unite described the Liberal Democrats’ position not only as reckless, but as a farce and a fudge, and that is exactly what we have here—[Interruption.] The Chief Secretary says that if Len McCluskey agrees with it, it must be a nonsense position, but he agrees with the Prime Minister, so is the Chief Secretary suggesting that the Prime Minister’s position is ridiculous?

If wishing to end a continuous deterrent is such a reckless position, how does the hon. Gentleman think our other NATO allies in Europe can possibly cope with their current situation? Is he recommending that they should escalate their own nuclear posture?

The hon. Gentleman has got to try better. The fact of the matter is that France has a continuous-at-sea nuclear deterrent. Our deterrent is part of the nuclear umbrella for NATO. He and his Liberal Democrat colleagues would have more credibility if they came out and said that they were unilateralists, because that is a defendable and credible position, unlike the nonsense they are putting forward.

The importance of the nuclear programme to this country’s submarine-building capability has been overlooked in the Liberal Democrats’ proposals. My hon. Friend the Member for Barrow and Furness (John Woodcock) is right to point out its importance not only to his constituency but to constituencies in Derby and to the wider supply chain in the United Kingdom. If we are to maintain our sovereign capability, we have to do it by building submarines, and we cannot do that if we follow the Chief Secretary’s suggestion.

Perhaps the hon. Gentleman will also recognise that 25,000 people in Devonport’s travel-to-work area are dependent on defence, and this would have a very damaging impact on the local economy, which is a low-skills, low-wage economy.

The hon. Gentleman makes a good point. No doubt at the general election he will remind his constituents and others of the Liberal Democrats’ position. We have some indication of what they think of people in Barrow and Furness because the hon. Member for North Devon (Sir Nick Harvey) suggested that they could move to the Bahamas to find work if we killed off the submarine-building industry there.

But I have the quote here:

“The idea that you should produce weapons of mass destruction in order to keep 1,500 jobs going in the Barrow shipyard is palpably ludicrous. We could give them all a couple of million quid and send them to the Bahamas for the rest of their lives , and the world would be a much better place, and we would have saved a lot of money.”

If that is the Liberal Democrats’ policy, I am sure that the people of Barrow and other places in the supply chain will have a clear view on it. He will have a chance later to tell us whether he has changed his position on sending my hon. Friend’s constituents to the Bahamas.

I must chide my hon. Friend. If he reads the reports on alternatives to Trident, he will see that even the one on the future of Barrow-in-Furness makes the very important point that no one should ever argue for making weapons of mass destruction on the basis of employment, because there are alternative places for people to work. Both reports produced so far have said that alternative work could be found if we invested properly in other things. It is wrong to argue that employment is a reason for having weapons of mass destruction.

I am not saying that; I am saying that we cannot dismiss the fact that these industries do not just employ people. I am proud of the high-technology industries in this country that support the nuclear programme. If the Liberal Democrats are not proud of that technology and the individuals involved in it, then that is their position, but I am certainly proud not only of their skills but of the wealth they create for many communities across the UK. I agree that that is not the only reason we should have the nuclear deterrent, but it is a very important one.

I commend the hon. Gentleman for the strength of his argument. Let me point out—I am sure that he shares this view—that we came perilously close to losing this country’s submarine-building capability. That is a strategically important capability that we need to maintain, and it looks as though the Liberal Democrats are prepared to sacrifice it.

I did not want to go down this road because obviously the Conservative Government have learned the lessons from the mistake that they made in the 1990s which created the current problems with Astute. We cannot turn these vital skills on and off like a tap when we need them. I have heard various people say, “Is this a justification for Trident?” No, it is not, but we have to take it into consideration when forming policy, and the Liberal Democrats’ position set out in the review document clearly does not do that.

The hon. Gentleman said that the Labour party may reduce the number of successor submarines from four to three. What would be the implication of that for Barrow?

I did not say that, actually. I said what the Defence Secretary has said—that in thinking about the new nuclear submarines, we should consider whether it would be viable to have three. That is an option worth looking at. We would then have to bring forward the successor programme for Astute. If we deleted two boats—[Interruption.] The hon. Member for North Devon says, “It’s all right if we do it.” The fact is that if we went down to two we would have a deterrent that is absolutely useless. It would not save the £4 billion that the Chief Secretary suggested because unless we had mass lay-offs in the submarine-building programme, we would have to bring forward more work, including on the successor for Astute.

Is that not the exact point? Would it not be helpful if the Chief Secretary made clear whether he wants to save that £4 billion over 30 years and decimate Barrow and the submarine-building industry, or whether he will bring forward the work and eliminate all those savings?

My hon. Friend makes a very good point. These are questions that the Liberal Democrats and their nonsense policy have to answer.

The hon. Gentleman is making a very important point as part of what appears to be a shift in the official Opposition’s position on continuous-at-sea deterrence. I would be grateful if he would confirm what I think he is saying. Is it the case that he wants to maintain a minimum deterrent capability, which would most likely be four boats unless technological change suggested that it could be maintained with fewer than four boats?

That is exactly the case, and I think that the Defence Secretary has said the same thing. It will be achieved not by sticking a finger in the air and thinking of a policy, but by thinking about what we need to keep our nuclear deterrent credible and by maintaining the important continuous-at-sea deterrent.

As has been said, we are convinced that the only credible way forward for a minimum nuclear deterrent is a continuous-at-sea deterrent; otherwise, the UK would be vulnerable. The Chief Secretary’s suggestion would not only make the UK more vulnerable, but lead to a situation where we would not possess first strike or even second-strike capabilities. It would also be a significant escalatory factor if the UK stepped up its armed CASD posture. It is simply not credible and it is also very dangerous.

There are options that the alternatives review did not consider, so why are the Liberal Democrats set on the proposals outlined by the Chief Secretary? I think it is the old Liberal Democrat trick—many of us who have dealt with them in local government have seen this over many years—of trying to ride both horses at the same time. They want to appease the party’s unilateralist wing and persuade them that they are scaling down the nuclear ladder, while simultaneously claiming to the electorate that they have a credible nuclear policy, but they have been found out by the alternatives review.

The Liberal Democrats have commissioned a review in Government time, using taxpayers’ money and resources, in order to supplement their own party’s policy manifesto for 2015. I tabled a written question to the Chief Secretary yesterday asking how much the review cost, and I await his response. The Lib Dem plans have been found wanting and they are now scrambling around frantically for a bizarre policy solution in order to advance their much-heralded differentiation strategy, through which they are trying to place themselves between the Labour party and their coalition partners.

We have all waited for the publication of this report and I think we all genuinely thought it would suggest a credible alternative. Our position is clear: we are committed to the minimum, credible independent nuclear deterrent, which is why we put that policy to the House in 2006. I completely disagree with the Chief Secretary’s comment that this is the most thorough review undertaken. That is complete nonsense, because that review was done in 2006. He should also look at the three comprehensive reports commissioned by the Defence Committee, which covered all the issues.

As my right hon. Friend reminds me, we also consulted on the issue and did not conduct our review behind closed doors, as was the case with this one.

We also believe that the best way to deliver the nuclear deterrent is through a continuous-at-sea deterrent. The review does not appear to suggest anything to the contrary. In fact, it reinforces our point.

The Chief Secretary asks how much longer I have left. It is taking time to get through the nonsense he has come up with, but I will draw my remarks to a conclusion. I know that this is not very comfortable for the Chief Secretary, but he is going to have to sit there and listen.

It is a serious subject. I just wish that Liberal Democrats would treat it seriously, rather than coming up with the nonsense that they keep peddling.

The alternatives review reinforces my point. On page 5, it states:

“The highest level of assurance the UK can attain with a single deterrent system is provided by SSBN submarines operating a continuous at sea deterrence posture.”

On page 10, it states:

“None of these alternative systems and postures offers the same degree of resilience as the current posture of Continuous at Sea Deterrence, nor could they guarantee a prompt response in all circumstances.”

I could not put it better myself. Breaking CASD would involve an unacceptable downgrading of our capabilities.

To return to the issue of cost, we have been told by the Liberal Democrats that the alternatives to Trident would be cheaper, but their review shows that to be complete nonsense. We were told by the Chief Secretary yesterday that the review was not about savings, but about the nuclear deterrent.

In conclusion, the Liberal Democrats’ review has not only unmasked their political posturing, but reinforced the case for the policy voted for by this House in 2006. [Interruption.] I am sorry that the right hon. and learned Member for North East Fife (Sir Menzies Campbell) is muttering. When he is put under detailed examination, he will have to explain the nonsense that he peddled in the run-up to the last general election, which his party’s review has completely discredited. Perhaps he has not read the report. The Liberal Democrats must want to have some credibility. I know that it is not unusual for them to look both ways and ignore the truth, but the report clearly discredits most of the things that he has said over the past few years.

The alternatives review has looked at the alternatives and come forward with the conclusion that we all thought it would reach: the minimum credible nuclear deterrent for the UK is submarine-based continuous-at-sea deterrent. [Interruption.] Well, that is what it is saying—

Order. That really is enough. It is impossible for Hansard to keep a proper record of this debate when senior Members keep shouting across the Chamber and the Member on their feet then replies. Either we have interventions or we do not. We are up against the clock and I would appreciate it if we could get on to the Back-Bench speeches.

Thank you, Madam Deputy Speaker. I await the examination of the report by the right hon. and learned Member for North East Fife and his justification of his comments over the past few years on this subject.

The standards that we set in this area are important not just in terms of cost. I know that the Opposition and the Government are conscious of the need to ensure that we not only get value for money, but we have a—

I thank the hon. Gentleman for giving way. Given that he is suggesting that we should retain a like-for-like deterrent, what cuts to conventional services is the Labour party proposing? Would it cut the destroyers or the joint strike aircraft?

Oh my God! Sorry, Madam Deputy Speaker, but I am getting a bit frustrated with these people who clearly do not know what they are talking about. If the hon. Gentleman looks at the equipment programme, he will see that the deterrent is in there now. He and his colleagues are peddling the nonsense that we can have either Trident or something else in the defence budget. Is he suggesting that if we cut Trident, the money would be ring-fenced for defence? That would be the first time that the Liberal Democrats have been proactive in support of defence matters.

The alternatives review has discredited the alternatives completely and exposed the reckless policy of the Liberal Democrats on this issue. We await the clear examination of their policy at the Liberal Democrat party conference, where they will no doubt look both ways—portraying themselves as unilateralists while at the same time arguing that they are strong on the nuclear defence of this country.

Order. At the beginning of the debate, Mr Speaker indicated that he was minded to set a time limit of six minutes depending on how much time was taken up by the opening remarks from the two Front-Bench spokesmen. We have made up some time with speeches that were commendably short, so I will start the time limit at seven minutes for Back Benchers. However, that might need to be reviewed if others are not disciplined and do not stick to the seven minutes or less limit.

I will begin by saying that this is not the most comprehensive review of this subject carried out in recent years: the previous Labour Government carried out a comprehensive review. I can say that with some confidence, because one of the first things I did as Defence Secretary when we came into government was to ask to see that work and check whether its assumptions and costs were still valid. It was my view that they were, and that continuous-at-sea deterrence still represented the best system and best value for our nuclear deterrence.

In our review, we looked at the previous Government’s review and at the systems that have since been rejected again. No Member wants to have an air-launch system or a silo-based system in their constituency. At the time, the Liberal Democrats put forward a proposal on the cruise-based system that they believed to be credible. We, of course, maintained our belief that CASD was the best, along with a replacement for the Trident programme.

There are a number of reasons why I was happy for the review to go ahead. In particular, it would show the Liberal Democrats that the cruise-based system was a non-starter. First, it would be too expensive. It would require research and development for the missile system and for changes to the submarine programme. It would be slower and more easily intercepted. It would require our submarines to be closer to target, and therefore more likely to be detected. It would also—no small point—be illegal under the treaty on the non-proliferation of nuclear weapons. It was a non-starter. I am therefore pleased that the Chief Secretary, who is not in his place at the moment, came to the conclusion, rather belatedly, that it would be good to keep the Trident replacement system. It is a gain for the whole House and the country that the Liberal Democrats have seen sense.

What is deeply depressing, however, is the willingness of the Liberal Democrats to abandon CASD. It has been the position of both major parties—the Labour party and the Conservative party—to have CASD based on four boats, or fewer if technology allowed. Let us be frank: in the foreseeable future, technology will not allow us to go below four boats. We need one going out, one coming in, one in refit and one in training. It is not possible to maintain what we have and what we want at lower levels than that, given present technology. If we go down to three, CASD cannot be guaranteed. If we go to two boats, we cannot have it at all, so that is an unrealistic proposition.

What are the Liberal Democrats saying with this policy? They are saying that we would abandon CASD, but deploy at times of increased international tension. What does any Member think would happen to international tension if we deployed a nuclear system that was not otherwise deployed? That would be a crazy foreign policy. I have to say to my Liberal Democrat colleagues that it is all very well to talk about stepping down the ladder, but if the bottom of the ladder is hanging off a cliff, that is not exactly a sensible manoeuvre.

On cost, the Chief Secretary said that they would save £4 billion over the lifetime of the programme—£4 billion over a 34 to 50-year period. That £4 billion is the equivalent to less than two weeks’ spending on the national health service, or six days of what we spend on pensions and welfare. This is supposed to be value for money. For that infinitesimally small saving over a 50-year period, they would abandon a crucial element of our national security—a very interesting definition of value for money.

For the sake of clarity, it is important to stress that in the report the only options for Trident are a four-boat fleet or a three-boat fleet. That is where the £4 billion would come into it. The report does not even consider or cost a two-boat fleet, because it would be impossible to reinstate to a higher level of readiness.

It is not possible to put in monetary terms the risk that moving to a two-boat fleet would pose to the UK. They are completely different currencies. It is ridiculous to say that there would be a £4 billion saving, given the monumental disruption it would cause to our submarine-building programme and all the jobs likely to be lost, as the hon. Member for Barrow and Furness (John Woodcock) pointed out many times. The calculations in the report are fraudulent economics.

The crucial question to be asked by anyone who wants to dismantle or diminish the CASD posture is: what will the world look like in 30, 40 or 50 years? It is all very well to say, “The risk assessments says that at the moment it’s okay”, but we do not know what the risk assessments will be in the future, and it is not our job to play roulette with the security of future generations in our country. We are being offered 50 years of protection from nuclear blackmail for the people of our country. There are those who say that £20 billion or more of capital costs is too much for 50 years’ protection from nuclear blackmail, but that it was all right to spend £9.5 billion for six weeks for the Olympics. We need to get our priorities right in this country and recognise what is important in the longer term.

CASD gives us secure insurance that is proven. It is the best deterrent, and to say anything other is political posturing, I am afraid. As has been said, we could drive a nuclear submarine through this report. We all like a good joke in politics, but this is no laughing matter. If it is a joke, however, let us hope it rebounds on the Liberal Democrats, not on the people of this country.

The political class in this country and others struggles to communicate and maintain credibility with the electorate. It is not always our fault, but sometimes we are to blame, and when we commission such a report and present it in this manner, we do serious damage to our credibility when talking to our electorate. In my opinion, the report was born of unworthy motives and conducted without any outside consultation, and to present it with the kind of hyperbole we have heard tonight—as the most comprehensive examination of our nuclear deterrent in a generation—is clear and utter nonsense. The report picks apart nothing in the 2006 White Paper; indeed, despite the best efforts of the right hon. and learned Member for North East Fife (Sir Menzies Campbell) at the last general election, it confirms the basic underpinning of the report and denies the credibility of what was said at the last general election: that we can have a cheap nuclear deterrent.

Of course, there is the question of whether we should have a nuclear deterrent at all. It is raised in all our constituencies all the time and is a perfectly reasonable question. Some Members believe and say openly that we should not have one, while others, I think, believe the same, but do not say so openly. The first question, then, is whether we should have one at all, but the report was not commissioned to examine that question; it was commissioned to examine the second question, which inevitably flows from the first: if we decide to have a nuclear deterrent, what kind should it be? What is the best system? What is affordable, effective and a real deterrent? That is where the report falls down.

There is no such thing as a non-credible or a less-credible deterrent. There can be no such thing as a part-time deterrent. To be a deterrent, something has to deter. Doing anything less than deter stops a nuclear deterrent being a deterrent at all. It turns it into what? Potentially, at times of crisis, it turns into an invitation; it most certainly turns it from a deterrent into a weapon. If we look at what underpins the White Paper— and as the previous speaker clearly stated—we have seen that such a weapon would be dangerous to deploy. How, when and in what circumstances would it be put to sea? How would we disguise, at a time of rising tension, that we were doing that? It would be dangerous to deploy and difficult to sustain. It is all right to say that if we have three boats, we could, for a time in some circumstances, up our level of deterrent and go back to continuous-at-sea deterrence. Yes, we could do that for a while if we got ahead of the crisis, stepped back to CASD, deployed a boat at sea and kept it at sea throughout that time. But with three boats, for how long could we do that?

The Government and the Labour party accept—indeed, it would be nonsense not to accept it—that technology may change the need for a fourth boat. If it does, why on earth would we do anything other than have three boats? However, if technology does not change those basic parameters, we will lose our ability to deter for a considerable time. This is not something we can just rescale in a matter of months; it would take years to rescale and we would therefore be rendering our deterrent non-sustainable.

This report does not ask an honest question and I do not believe it was an honest process, but the review has at least flushed out the issue of whether Trident can be done on the cheap. I would not want to have an examination in a cheap operating theatre by a doctor who had been trained on the cheap, and I would not want a deterrent that was done on the cheap. If we are to have a deterrent, let us have a deterrent that deters, as that is the only one worth having.

I commend my right hon. Friend the Member for Inverness, Nairn, Badenoch and Strathspey (Danny Alexander) on bringing this piece of work to fruition, and I believe it has genuinely taken an open-minded look at the whole issue. The review did not set out at the beginning by offering preconceived conclusions to those carrying out the work, and I believe it has been a worthwhile exercise. I also note that the principal reason why alternative systems were found not to be viable was not—as some have suggested—because they were not technically viable. In contrast, it was because the length of time such alternatives would take, and the amount of money it would involve to equip a warhead to an alternative system, would make such alternatives prohibitive in the medium term. That is the expert view of those tasked with looking at the matter. If that is the conclusion to which they have come, I for one would not seek to question it and we must accept it.

The second part of the study, which looks at alternative postures, concerns the debate that this report can now seek to inform and trigger.

Not at the moment.

Given that this report was commissioned by a Government who are a coalition of two parties with fundamentally different opinions on the issue, it was never going to come forward with proposals. It was about considering the alternatives and informing the debate that might follow.

I contend that nobody can rationally argue that the nature and scale of the nuclear threat that the United Kingdom faces in 2013 is the same as it was at the height of the cold war. Then we had a known nuclear adversary, the Soviet Union, that had British targets in its sights and we, similarly, had Soviet targets in our sights. We believed that it might strike at a moment’s notice and we therefore thought it was essential that we were ready at a moment’s notice to strike back. But 25 years after the Berlin wall came down, one cannot rationally argue that the threat we face today is the same as it was then. We can debate what threats we might face in the future, but we cannot argue that the threat we face today is the same as it was in 1980.

We are talking about building a system that will protect us against the potential risks in 20, 30 or 40 years. The year before the Berlin wall came down, no one could have predicted the world we would be in today. No one can predict what the world will look like in the future. The hon. Gentleman is asking us to take an irrational and dangerous risk.

I agree entirely with my right hon. Friend that we must consider the threat we might face in 20, 30 or 40 years’ time, so we must therefore ensure that we have a nuclear deterrent in 20, 30 or 40 years’ time that is capable of deterring the threat that we might face at that point. My point is simply that the threat we face today is not the same as it was at the height of the cold war. It therefore cannot make sense to operate it on a 24/7 continuous basis facing a threat that simply does not exist at the moment.

I understand the view of those who say that we must retain enough capability to ensure that, in the future when we face threats we cannot anticipate today but know intuitively could come, there is enough of a deterrent to repel them. That is perfectly logical, but it does not make sense for the nuclear deterrent—uniquely among our military capability—to be on patrol the whole time when even our national security strategy has stressed that it is for a second-tier threat and when we do not use our military capability to deter the primary threats on that continuous patrolling basis.

To answer the points made by my right hon. Friend the former Defence Secretary, I am not saying that it might not be necessary in the future to crank up to a more rigorous posture—it might well be—but I do not see how anyone can rationally argue that we have to do that at the moment. The idea that the nuclear capability has a deterrent effect at all only by being patrolled 24/7 is clearly absurd. All the rest of our capability has a deterrent effect against a variety of aggressors in a variety of scenarios and we do not see the need to exercise any of it on a 24/7 basis.

I could just about stay with the hon. Gentleman’s argument if he was saying that we ought to build four submarines but not send them all to sea until the situation became worse, but he is not saying that. He is saying that we should build only two or three such submarines, which would mean if the situation got worse, we would not be able to reinstate continuous-at-sea deterrence because we would not have the submarines. Without the submarines, we cannot have the posture, much as he might like to reinstate it when the situation gets worse.

I can agree to the extent that we must ensure that we build enough capability that we can mount the deterrent we will need at the point that we need it. What that will comprise is a matter for further debate and further study and I note with interest that even those on the Labour Front Bench and the former Defence Secretary, the right hon. Member for Coventry North East (Mr Ainsworth), acknowledge that it remains to be seen whether we need four or three to do that.

Just let me see whether I understand the hon. Gentleman’s position: is he saying that we should build enough submarines to be able to go back to continuous-at-sea deterrence and to maintain it at any point at which the threat increases?

I am certainly saying that I think we should have the ability to go back to continuous-at-sea deterrence when we think we need it. I do not know that I would go so far as to say we should be capable of sustaining it indefinitely—I think that is unnecessary in scale—but I do think we should be capable of sustaining it for periods of time when there are heightened tensions. The problem we face is that we run the risk of having a Rolls-Royce nuclear deterrent at the expense of having an Austin Mini as the remainder of our defence capability. During the very decade when expenditure on the Trident replacement will be at its height, there will be a long list of other high-profile, highly important defence projects competing for what we all know will be very limited defence resources.

There are some obvious examples. We are going to put the joint strike fighter on to our two aircraft carriers, and we do not have the slightest idea at this stage what the unit cost of them will be on a through-life basis. We are going to build the Type 26 frigate. We have got to do something about the Army’s equipment programme given that the future rapid effect system programme is now in tatters as a result of the last few rounds of cuts we have had to make. We are going to need another generation of remotely piloted aircraft. We are going to need more amphibious shipping when HMS Ocean goes out of service in 2018. We need more helicopters. We need more ISTAR assets, and we need to deal with the cyber-threat, which the national security strategy said was one of the primary threats and in which we are investing modestly but nowhere near enough.

If anybody thinks that the resources committed to defence, or that can be anticipated as being available to defence, are enough to pay for all of those on the scale everybody in Government, and probably in the Opposition as well, would want to see and think is necessary in terms of our own strategic defence and security review, something is going to have to give. We cannot afford to do all that and have a nuclear deterrent scaled to deal with the menace of the cold war 25 years after the Berlin wall has come down and 19 years after we and the Russians de-targeted each other.

It simply is not the case that in order to get a deterrent effect from our military capability we have to patrol it all the time. That is absolute nonsense. The British, the French and the Americans have a posture of continuous-at-sea deterrence; the Russians and Chinese do not. The Indians and the Pakistanis take each other’s nuclear weapons perfectly seriously, but that does not mean they patrol with them the whole time. It is complete nonsense to say we have to do it on that basis.

I hope the report published yesterday will inform a national debate about this before a decision is taken in 2016, and when that is done the next generation of the nuclear deterrent will have to compete for funds alongside all the other platforms I have described, which are far more relevant to the threats we actually face.

It is a pleasure to follow the hon. Member for North Devon (Sir Nick Harvey), even if I think it is regrettable that he did not take this opportunity to clarify the remark about sending Barrow workers to the Bahamas, which caused real offence in my constituency. I do acknowledge, however, that he has spent a lot of time over the past two years on this review, even if I find his conclusions completely wayward.

This was supposed to be the Liberal Democrats’ opportunity to show that they could be trusted with the defence of the realm, and I have to say they have blown their chance spectacularly. Smashing the hegemony of a blinkered defence cartel that silenced any debate on the deterrent was heralded as one of the great Lib Dem wins from the coalition negotiations. We can imagine Lib Dem Members reassuring their concerned activists: “Yes, we’re more unpopular than we’ve ever been. Yes, we’re breaking our promises to students. Yes, we’ve given up any hope of being called the progressive party for a generation. Yet we bring you a referendum on the alternative vote, and we will challenge the tyranny of Trident renewal that has bewitched the two other parties.” It has not gone very well, has it?

As I understand it, now the Liberal Democrats’ position is pro-Trident. It might be because of the fact that they are only going to have two submarines, but is that not a major change from the last general election?

I would describe it as a complete collapse in the Liberal Democrats’ position. Two years on, we have a taxpayer-funded document—how much did this process cost the taxpayer, by the way? The document basically confirms what we duped fools have been arguing for years—that unless people show their true colours and come out as unilateral disarmers, and in doing so advocate a path that we strongly believe would make the horror of a nuclear war more likely, there is no credible, cost-effective alternative to the fundamentals of the existing plan to replace our fleet of deterrent submarines.

The alternative review rejects as unworkable and even more expensive what had long been the Liberal Democrats’ preferred option—some sort of mini-deterrent. Then the fall-back plan of halving the number of replacement Vanguard submarines to two, fervently briefed to the newspapers over the weekend, turns out not to have been considered by the review at all. Would anyone like to explain this? Have Liberal Democrats realised that every idea they have put forward so far has collapsed under scrutiny? Did they come to a view that it was best not to test this one in the official review, lest those pesky facts and figures ruin it like all the others?

The hon. Gentleman may be aware that all the talk about the Liberal Democrat conference considering a two-boat option comes from a Liberal Democrat document that has been drawn up by a Liberal Democrat group. When I asked the Chief Secretary earlier today at a briefing whether any copy of the review was going to be taken to the Liberal Democrat conference for consideration, he said, “Well, I might take a copy, but it will just be in my briefcase.” In other words, the review is not the document that the Liberal Democrats are going to consider. They are going to consider a completely different document making completely different recommendations, which the review did not even bother to consider.

The hon. Gentleman is right. If we were living through a Monty Python sketch, this would be the point when the army major intervenes and says that this is all getting too silly and we have to stop it at once. But of course the consequences for the nation’s security, and the 13,000 people directly employed in Barrow and across the UK, would be bitterly serious if the Liberal Democrats had their way on their part-time deterrent idea. That is why it would be a very good thing if this shambolic process now sunk without trace. Even their own document makes it clear just how hopeless an alternative a part-time deterrent would be. It states that

“a 3-boat fleet would risk multiple unplanned breaks in continuous covert patrolling as well as requiring regular planned breaks for maintenance and/or training.”

They are effectively suggesting that we pay billions for something that we cannot be sure will be available to do the deterring when needed.

Proper analysis of the figures makes clear the economic folly of the argument. The Chief Secretary told me that he had considered the cost of maintaining Britain’s submarine-building capacity at Barrow and elsewhere, but his own document makes no suggestion, as far as I can see, that the savings take account of that. It suggests that the extra costs from 2025 of bringing forward the next submarine programme—the successors to the Astute—to avoid a crippling gap in the order book of the shipyard are simply not considered in the £4 billion saving. When he sums up, will the Minister finally confirm what the Chief Secretary has so far avoided admitting—that these relatively modest savings would be completely wiped out by the extra cost?

The choice that the next Government but one would face would be either to leave a gap in construction so large that it could end the country’s capacity to build submarines for ever, sacrificing all those 13,000 jobs, or to end up saving no money at all by embarking on a whole new submarine-building enterprise before it is needed by the Royal Navy.

Will the hon. Gentleman confirm that the figures are actually worse than that? The savings that the Chief Secretary set out will not accumulate until far later in the period, while the costs that the hon. Gentleman is describing would be incurred very early in the process.

Absolutely. On the Liberal Democrats’ official figures, the savings will not even start to accrue until 2025, but by that time work would have to be well under way in Barrow shipyard and the supply chain to make the costly preparations for the Astute successor submarines. The Liberal Democrats need to come clean about the extra cost, because it makes a mockery of what the right hon. Gentleman rightly said are incredibly modest savings over a 30, 40 or 50-year period.

It should be remembered that the capacity to build nuclear submarines is one of the very few sovereign protected capabilities deemed so important and sensitive that the overwhelming majority of construction must be carried out on British soil. The submarine supply chain—centred in Barrow, but stretching from Aberdeen to Plymouth—is so advanced and finely tuned that any period in which it is left idle risks destroying it entirely. That is the lesson of the mass redundancies in my constituency in the 1990s. It is a great shame that some of those who now have the privilege of governing do not seem to have learnt a thing.

On a point of order, Mr Speaker. I am distressed to raise this point, but for some reason the Chief Secretary seems to have adopted a posture of preserved deterrence—that is, he is not here. He left the Chamber shortly after the Opposition spokesman sat down, in a three-hour debate of such importance. I am afraid that I regard that as rather a discourtesy to the House. Did the Chief Secretary give a reason when he left the Chamber and, if not, should he not have done so as a courtesy to the House?

I am not aware of whether the Chief Secretary did or not, because I was not in the Chair at the time. The hon. Gentleman has made his point and it is on the record, but nothing disorderly has taken place. There is no breach of order; the Chief Secretary has no obligations in this matter, but I note what the hon. Gentleman has said.

May I say what a pleasure it is to follow the hon. Member for Barrow and Furness (John Woodcock)?

It is a pleasure to have an opportunity to talk about the important issue of retaining Trident and our nuclear deterrent. Representing Devonport, which is the only UK dockyard with a nuclear licence, I can speak with some relevance about how my Plymouth, Sutton and Devonport constituency is on the front line of defending our maritime interests. I am afraid to say that, if what the Liberal Democrats announced yesterday were to come true, it would have a devastating impact on Plymouth’s travel-to-work economy and skills base. I hope that my comments will carry the support of all Members of Parliament in the travel-to-work area, including the hon. Member for Plymouth, Moor View (Alison Seabeck), who I understand cannot participate in this debate as she is in the shadow Defence team.

Retaining Britain’s nuclear deterrent—a strategic concept that seeks to prevent war—is a key element and cornerstone of the defence of our country. It is a vital ingredient in our membership of NATO and our relationship with the United States of America, our strongest ally, and ensures our seat on the UN Security Council. Britain’s nuclear deterrent helps to prevent would-be aggressors and other countries from attacking us or using their nuclear arsenals to try to blackmail us.

Our ownership of this highly successful deterrent came about following the bombing of Hiroshima and Nagasaki, which brought about a dramatic end to the final phase of world war two. Like a slap in the face, it shocked the world with its catastrophic implications. The implications of that event were so dramatic that no one has ever sought or dared to push international conflicts to a point where any country has had to use nuclear weapons, which have been Britain’s most effective insurance policy. Indeed, the development of nuclear weapons since Hiroshima and Nagasaki continues to have a significant impact on the veterans who were dispatched to Christmas island and other places to take part in the very tests that made the nuclear deterrent that we are discussing today possible. We must remember that we owe them a great debt of gratitude. Indeed, it would be most helpful if the Minister paid tribute to them in his winding-up speech.

The nuclear deterrent continues to play a significant role in maintaining peace throughout the world. Unpredictable countries such as Iran and North Korea, which are threatening to develop their own nuclear capabilities, make it vital that Britain retains its nuclear deterrent. It continues to act as a pressure point, as conventional capabilities cannot and will not have the same deterrent effect as nuclear weapons do. To quote the Prime Minister, it is the “ultimate weapon of defence”.

The deterrent is not just a defence weapon, however; it is also a key part of our economy, nationally and locally. It helps us to retain our skills base, especially in Devonport, which is part of my constituency, and in Barrow and Furness. Devonport dockyard, which is responsible for refuelling and refitting our nuclear submarines, is a vital part of our local economy, as more than 25,000 people in the Devonport travel-to-work area depend on defence for their livelihood. Yesterday’s mind-boggling proposals by the Liberal Democrats that the UK should move away from a continuous-at-sea deterrent and reduce the number of submarines from four to three, or even two, would have a devastating impact on the city’s economy. Their insistence that the main gate should be delayed until after the 2015 election is producing real uncertainty in the local economy.

If the Liberal Democrats’ proposals were to become a reality, they would not only damage 25,000 people’s livelihoods but have a major impact on our low-skills and low-wage economy. They would also damage the job prospects of the young people who are about to start at Devonport’s university technical college, which is set to give youngsters an education that will eventually deliver a skilled work force who could be employed in our dockyard. That would be most unhelpful. A reduction in the number of nuclear submarines would mean less refitting work, and the highly skilled work force in our dockyard would have to move elsewhere to find work.

Given the importance of Devonport to the south-west’s economy and the defence of our nation, I find it extraordinary that the Liberal Democrats are doing everything they can to delay the main gate for the Trident replacement. Perhaps this is going to be one of the bargaining tools that they will use in any negotiations that they might have with Labour, should the result of the next general election be a score draw—I very much hope that that will not happen—as it was in 2010. Sadly, the Leader of the Opposition has not said that the future of four nuclear submarines and the continuous-at-sea deterrent would not be up for negotiation in any potential coalition or supply and demand agreement, and I would be grateful if his position on this could be confirmed. At least we now know for sure that there is only one way in which we can be certain of maintaining our nuclear deterrent. That is to have a Conservative victory at the next election, which would ensure that our country could continue to play a significant part in global politics and that we had the necessary tools to defend ourselves.

I am pleased to be able to take part in a debate on the alternatives review, which many people with different views on deterrence theory believe to be fundamentally flawed because it did not consider all the alternatives. That is more relevant to Scotland than it is to many other places because Scotland probably has the highest megatonnage of weapons of mass destruction of any nation in the world.

The Liberal Democrats must be living in a parallel universe if they think that people in Scotland do not think it important to consider all the options, not least because the majority of our public representatives have voted against Trident renewal. In the Scottish Parliament on 14 June 2007, 71 Members of the Scottish Parliament voted against Trident renewal; only 16 voted in favour. In this place, on 14 March 2007, 33 Scottish MPs voted against the Trident renewal proposals, with only 22 voting for them.

This is the view not only of parliamentarians; it is consistently the view of the majority of people in Scotland. In October 2012, a YouGov poll showed that 57% of people in Scotland thought that the Scottish Parliament should have more powers to bring about the removal of Trident from Scotland. In September 2011, an Angus Reid poll for the Sunday Express showed that 57% of people in Scotland did not agree that Trident should be based on the Clyde. In 2010, a YouGov poll showed that 56% of people in Scotland believed that we should not buy a replacement for Trident. It goes on and on.

Let me draw the hon. Gentleman’s attention to the report produced by the Public Administration Committee, which experimented with deliberative polling to find out how to inform national strategy at the heart of government by engaging with the public. What did the poll conducted on our behalf show? The final question asked whether the United Kingdom should order four new submarines or give up nuclear weapons altogether. In Scotland, 49% were in favour and 43% were against.

As the hon. Gentleman knows, there are always outliers in polling—[Interruption.] I reflect on the fact that the Scottish National party is the only majority Government in the United Kingdom, receiving more votes than all of the three UK parties combined on the second vote. The hon. Member for Harwich and North Essex (Mr Jenkin) can laugh, but he represents a party that is the worst-performing centre-right party in the industrialised world. That is how badly it performs in Scotland. Even when his friend Lord Ashcroft polled in Scotland, he found that in principle 48% of Scottish respondents oppose the UK having nuclear weapons.

The Liberal Democrat review would have been worthy, as the former Defence Secretary the right hon. Member for Coventry North East (Mr Ainsworth) suggested, if it had taken evidence and spoken with other people—people outside the Ministry of Defence, people outside government. The Lib Dem spokesman could have met the Scottish Trades Union Congress and spoken to its general secretary, Grahame Smith, who said that renewing Trident “will cost Scotland jobs”. We might not all agree with those views, but they are views of important people, and if we are going to have a review that looks into alternatives, surely the relevant people should be spoken to.

Did the right hon. Member for Inverness, Nairn, Badenoch and Strathspey (Danny Alexander) meet the Scottish Trades Union Congress? No, he did not. Did he meet Unison, whose Scottish general secretary condemned the Government’s decision to replace Britain’s Trident nuclear fleet?

No, I want to make some progress.

Did the right hon. Member for Inverness, Nairn, Badenoch and Strathspey look at the STUC report, published in November 2012, which said:

“Given that Scottish trade unionists appear to strongly support the removal of Trident, the question of the ‘Better Together’ parties is how else can Scotland and the UK be freed of Trident other than through a vote for independence?”

That is the trade union view, but what about other important actors in public life in Scotland?

What about the Churches, for example? What of the views of the Moderator of the General Assembly and of the Roman Catholic Church in Scotland? I quote:

“On behalf of the two largest churches in Scotland, from where the UK’s Trident nuclear weapons are currently deployed…This planned renewal of Trident is contrary to international law and opposed by the majority of people in Scotland…Scotland’s churches have a long history of opposition to nuclear weapons. In April 2006 the Catholic Bishops of Scotland called for Trident to be decommissioned rather than renewed, and urged that the money saved should instead be spent on aid and development…In May 2006, the General Assembly of the Church of Scotland reiterated its strongly-held view on the immorality of nuclear weapons and called on the Government not to renew Trident, stating that:

‘To replace Trident would represent a further announcement to the world that safety and security can only be achieved by threatening mass destruction; this is to encourage others to believe the same, and thus to hasten proliferation.’”

Apparently, the Liberal Democrat review did not deem it important enough to speak to the Church of Scotland, the Roman Catholic Church, the Muslim community in Scotland or other faith leaders, all of whom oppose the renewal of Trident.

We are aware of the view of democratic representatives in Scotland, the view of the voting public, the view of the Churches and the view of the trade unions, so what about the voluntary sector? The Scottish Council for Voluntary Organisations says:

“Let’s call time on outdated Trident. They are an outdated hang-up from a past that bears little resemblance to the present political climate, yet Trident missiles still remain armed and dangerous in their silos in Faslane.”

Did the review speak to the Scottish Council for Voluntary Organisations? No, it did not. There are real alternatives, and we disagree on what they might be. My alternatives—the ones I prefer—would be to take Scotland’s share of the Trident nuclear missile system and spend it on something that is, frankly, useful. The Scottish taxpayers’ annual contribution is £163 million. That could train nearly 4,000 junior Royal Navy officers, or nearly 2,000 Royal Marine officers. It could train nearly 4,000 nurses, or more than 4,500 teachers. It could build between 13 and 20 single-stream primary schools, or between five or eight secondary schools, or between five and eight community hospitals. The list goes on. Those are real alternatives, but they were not considered in the review.

People need not hear that only from the Scottish National party. This is a rare occurrence, but let me quote from Scotland’s great Labour-supporting newspaper, the Daily Record. Today’s editorial, headed “People do not want Trident”, states that

“the one option not put forward was the one most would prefer—scrapping the weapons… It was left to the SNP and the Greens to give the majority view from Scotland.

Writing for today’s Record, SNP defence spokesman Angus Robertson says we should and could scrap Trident.”—(Laughter.)

The irony that is surely lost on the representatives of the three United Kingdom parties in the House is the fact that the strongest Labour-supporting newspaper in Scotland is endorsing the view of the Scottish National party. The editorial ends with the words

“It’s hard to disagree.”

Yesterday we were able to read the Government’s much-anticipated report on Trident and its alternatives, and I am delighted that it confirmed that the most effective and value-for-money option for the deterrent was a four-submarine CASD. How vexing, though, for the civil servants who worked so hard on it that half, or more accurately one seventh, of the Government have decided to disregard those findings, and to promote an option that was not included in the report’s brief because it was considered to be too ludicrous: a two-boat, part-time deterrent, which, as we all know, is no deterrent at all.

I would not go so far as to say that some of my best friends are Liberal Democrats, but I am sure that their hearts are in the right place. Sadly, the location of the collective Liberal Democrat head is not always obvious; certainly, on this issue they seem to have taken leave of their senses. Yesterday the Liberal Democrats were in chaos, reeling from the discovery that the three-boat option did not deliver the savings for which they had hoped. In scenes reminiscent of Mitchell and Webb’s “Numberwang”, they ran around Whitehall and Millbank yelling different numbers in the hope that one of them might strike a chord.

Perhaps a more appropriately named game show to describe yesterday’s endeavours would be “Pointless”. Let me explain why. The report puts the cost of two new submarines at £10 billion, the cost of three at £14 billion and the cost of four at £16 billion, excluding the attendant costs of missiles, warheads and infrastructure. According to the Liberal Democrats, those figures plainly show £6 billion of waste, but that analysis reveals a skewed sense of value for money. My understanding of the figures is that we could spend £16 billion on something or £10 billion on nothing, and the Liberal Democrat preference for the latter option has led me to conclude that it may not be a coincidence that the MOD budget was balanced only when Main Building became a Liberal Democrat no-fly zone in the last reshuffle.

In the absence of the Liberal Democrat head, it is perhaps not unsurprising that they are ruled by their heart, which in truth yearns for UK nuclear disarmament. Certainly the former Defence Minister, my hon. Friend the Member for North Devon (Sir Nick Harvey), when debating the matter with me yesterday on the BBC, would not agree that we could now proceed to produce two submarines and have a debate about the others later. If he had been pro some kind of deterrent, he would have agreed.

It may or may not be the case that we face no nuclear threat at the moment—although how would we know, because we would have deterred it?—but we cannot know what the future will bring. That point has been well made by several Members today. The Liberal Democrat position is contingent on the continuation of the current international climate, which, I remind Members, is influenced by CASD. Do the Liberal Democrats know something that we do not? Does their influence reach places that we cannot reach? Has the Tigger-like charisma of my hon. Friend the Member for Cambridge (Dr Huppert) and his cycling crusade, for which I salute him, had such an impact on the bicycle-loving populace of China that, should that state fall into malign hands, we need only deploy him on his bike to avert disaster? Or perhaps the Business Secretary has been able to persuade North Korea and Iran that they should not waste their time and treasure on nuclear weapons—after all, if they want to bring down the British Government, they need only give him a call. Or perhaps our polyglot Deputy Prime Minister has managed to negotiate with all prospective despots and promoters of state-sponsored terrorism to cut a deal of non-aggression for the next 50 years. If that is the case, I must counsel them that, in my experience, anything the Liberal leader might promise, even if it is in writing and witnessed by a Select Committee, might not actually come to pass.

The Liberal Democrats might very well know something that we do not, which might explain their relaxed stance on CASD, but we must plan and prepare for the possibility of aggression from a nuclear power, so let us consider the options. What about the middle way of a three-boat fleet? The report concludes that with only three boats there would be several unplanned, as well as planned, breaks in deployment over a given 20-year period, whereas that has not been the real-life experience of operating a four-boat fleet.

Even if we take the cited savings of approximately £3.5 billion on whole-life costs as correct, the average annual saving for the surrender of our continuous nuclear deterrent over 45 years of spending would be £78 million. As Trident and welfare are often presented as rival candidates for cuts, let us put that £78 million per year in context by comparing it with the approximately £160 billion annual cost of social security. Indeed, the total average cost, including missiles, warheads and infrastructure, of the whole shebang of a four-boat fleet would be about 1% of the non-pension welfare budget. CASD is value for money, and any alternative that is not continuous and is vulnerable to attack is neither value for money nor up to the job.

Today, I have made a light-hearted speech about a very grave subject. I have done so because I wish to persuade our coalition colleagues of the error of their arguments. In the past three years they have had a steep learning curve in the realities of power. On the evidence of their current antics, they have at least one more lesson to learn: the first duty of a Government, of any colour or combination of colours, is to protect the United Kingdom from these dread weapons. I urge them to do so.

I wish to begin by paying a couple of tributes, the first of which is to the hon. Member for North Devon (Sir Nick Harvey), who, despite my disagreements with him on this issue, was a superb Defence Minister. It baffles me why the Deputy Prime Minister sacrificed a Liberal Democrat voice in defence and foreign affairs in order to play some pavement politics for the next general election. I hope to dismantle some of the hon. Gentleman’s arguments in a little while, but it is worth noting that he was a very good Minister.

I also pay tribute to my hon. Friend the Member for Barrow and Furness (John Woodcock). I hope that the hon. Member for New Forest East (Dr Lewis) will not take it as an insult when I say that my hon. Friend has demonstrated again why he is now the House’s leading expert on the importance of the deterrent. All Labour colleagues would acknowledge that he has been a champion at ensuring that Labour Members fully understand the importance of the role his yards play in securing our nation’s future.

The hon. Member for North Devon claimed that the world was safer now than it was during the cold war, but I have absolutely to disagree with him. We are in a multipolar world where there will be emerging powers in the next 40 years, and the certainties we had in the cold war about the Soviet bloc no longer exist. It has been said several times, so I will not labour the point, but we are being asked to try to guess what the situation may be in 30 or 40 years’ time. It is not a criticism of the national security strategy from 2010 that it could not see the Arab spring coming less than 12 months ahead. Can he honestly tell us why he is so confident about the state of the world in 30 or 40 years’ time?

The Chief Secretary to the Treasury, who has scuttled off, I suspect to cry somewhere in the corner, has claimed that this is a comprehensive document. I tabled about 35 parliamentary questions to the Deputy Prime Minister earlier this year and was astonished at some of the answers that were revealed. There was no discussion with the United States, at any level, about the role of CASD. The Chief Secretary quoted President Obama at length, but he did not even have the courtesy to approach the United States embassy, the Pentagon, the State Department or the White House. There was no discussion with our NATO colleagues. There was no discussion with the French or any other international allies, and there were no discussions with the defence industry, save for cursory visits, I think, to Aldermaston and Barrow. There were no discussions with the local authorities that would be affected, and none with the Defence Secretary, except on one occasion during the two-year process. The Chief Secretary to the Treasury does not even have a pass for Main Building, which goes to show how little credibility he had. It is worth noting that he was flanked at all times by two heavies from the Ministry of Defence to ensure that he did not stray too far—[Interruption.] I think that they were heavies, albeit in the nicest possible way.

Has my hon. Friend heard the rumour—it might be untrue—that the Chief Secretary was not given access to the UK’s targeting policy?

If that were true, I would be absolutely astonished, but then nothing in this review and the work that was carried out by Liberal Democrat Ministers is credible.

The hon. Member for North Devon set out an argument that I have heard before that neither Russia nor China operates a CASD policy. I accept the premise of his argument, but he failed to mention—I am sure that it was inadvertent, not misleading—that both those countries have other platforms, so they maintain a continuous deterrent. We are the only one of the five that operates a single platform, so CASD is a continuous deterrent for us—there is no back-up plan.

I have a great deal of respect for the hon. Gentleman because after spending two and half years telling us why the Astute boat option would be sensible, he has at least had the courage to come to the Chamber and face up to the fact that he called that wrong. He argues that the problem was not a technical issue, but if his defence— pardon the pun—is that this is something that would cost billions and take decades to introduce, how is it not a technical problem?

It was not a technical problem in the sense that technically it would work; it was a financial and a time issue. I accept, as the hon. Gentleman says, that the option is clearly not a runner, but not because it technically would not work.

If the hon. Gentleman is not splitting hairs, he is splitting something or other, because if the option would cost billions of pounds and take decades to develop, the problem is technical. Any solution can be reaped with sufficient money and time.

The hon. Gentleman talked about how money could be circulated back into the MOD programme. We heard from the hon. Member for Moray (Angus Robertson) that the debate ends up being about things such as nurses and welfare, but the idea that the 4% lifetime cost savings as a result of having three boats would somehow be pumped back into the MOD’s conventional programme is not credible. The hon. Member for North Devon talked about how we could solve the challenges on the wider equipment programme, but we will have to do more with allies, whether on the joint strike fighter, interoperability or the remotely piloted air system. Work such as that started by the former Defence Secretary under the Lancaster House agreement is the way forward.

I noticed that the clock froze for two or three minutes while the hon. Member for Moray was speaking, but having listened to his speech, I felt that his argument had been frozen for 25 years. I was conscious that he did not want to use up his time by taking my intervention, so let me say that although he talked about the trade unions that could have been consulted, he could have spoken to the trade unions I met with my hon. Friend the Member for West Dunbartonshire (Gemma Doyle). If he spoke to trade union leaders at Faslane—the hon. Member for Argyll and Bute (Mr Reid) is in the Chamber but, surprisingly, he has not indicated that he wishes to speak—they would say that their future depends on this. I am sure that it was an oversight that the hon. Member for Moray did not suggest that those trade union leaders should have been consulted.

The hon. Member for Plymouth, Sutton and Devonport (Oliver Colvile), who I notice has not shown the usual courtesy by staying to hear the following two speeches before leaving the Chamber, made the rather bizarre claim that CASD could be guaranteed only by having a Conservative Government. If he was here, I would remind him that it was his Conservative Government who signed up to this review in the first place. I think that they need to hang their heads in shame for wasting taxpayers’ money and civil servants’ time—they have not wasted Defence Ministers’ time, because apparently they were not asked for their views—and there is absolutely no guarantee that they would not have a fudge at the next general election. The only way to guarantee a future for Barrow and for the Clyde is to send a clear message at the next general election by voting for my hon. Friend the Member for Barrow and Furness and other hon. Friends.

Labour Members have stated a few times that Labour might go down to three boats, so what would the hon. Gentleman say to workers about the jobs that would be lost as a result?

My hon. Friend the Member for North Durham (Mr Jones) has reiterated the point made by my party leader and the shadow Defence Secretary: we will maintain a continuous-at-sea deterrent. That is the exact policy adopted by the Defence Secretary. The only way we would not have a four-boat solution is if the technology moves on, which of course would completely change the configuration and the industrial strategy. I must say that the hon. Gentleman’s question was a classic Liberal Democrat last-minute jump-up. When he speaks, as I am sure he intends to, he can set out his argument. The reality is that the two-boat solution that he and his party support would devastate the community in Faslane.

In the past few months we have had several opportunities to debate nuclear deterrence. The hon. Members for Islington North (Jeremy Corbyn) and for Brighton, Pavilion (Caroline Lucas) and I, from our respectively opposite sides of the argument, successfully procured a debate on 17 January. Strangely enough, I did not hear many of these Liberal Democrat midway positions articulated on that occasion. The hon. Member for Islington North then secured a debate in Westminster Hall on nuclear deterrence and the non-proliferation treaty on 22 June, and I seem to remember that there were no Liberal Democrat contributions to that debate at all.

I think that it is possible to make a principled and coherent case either that we should have an effective and continuous nuclear deterrent or that we should not, but one cannot make a sensible case for having a part-time deterrent. I have looked at the report in some detail and will pick out a couple of elements that I regard as particularly significant. The very first sentence of the executive summary states:

“Deterrence rests on the notion of ‘unacceptable loss’—the ability to inflict a level of damage that a potential aggressor would judge outweighed any benefit they might gain by a particular course of action.”

Well, yes and no. It does not just rest on the notion of unacceptable loss; it rests on the twin notions of unacceptable loss and unavoidable loss. That is where the whole concept of continuous-at-sea deterrence is central, because if one thinks one has a chance of avoiding an unacceptable level of retaliation, one might well take that chance in the hope that one will not have to face up to it.

I have quoted before, and I will quote it again tonight, what was stated the first time a senior British defence specialist considered the concept of what in those days would have been called atomic deterrence. That was in June 1945 in a top secret report drawn up by a committee of defence scientists headed by Professor Sir Henry Tizard. He made a comparison between the atomic bomb, which at the time had not yet been tested or used against Japan, and the concept and practice of duelling:

“Duelling was a recognised method of settling quarrels between men of high social standing so long as the duellists stood twenty paces apart and fired at each other with pistols of a primitive type. If the rule had been that they should stand a yard apart with pistols at each other’s hearts, we doubt whether it would long have remained a recognised method of settling affairs of honour.”

However, if the duellists do not know whether the pistol is loaded, then even if they are standing only a yard apart they might just be reckless enough—“reckless” is the word that we hear time and again in the context of this Lib Dem policy—to take a chance. The whole point about nuclear deterrence is that it is unacceptable and unavoidable that a country will suffer nuclear destruction if it uses its nuclear weapons against a similarly armed country.

In the document, which was prepared by two civil servants in the Cabinet Office specially seconded from the Ministry of Defence, a number of strange concepts are articulated. One of them is familiar—continuous deterrence, which is referred to without quotation marks. Then the document refers to things called “focused deterrence”, “sustained deterrence”, “responsive deterrence” and “preserved deterrence”. I have studied this subject for at least 31 years and I have never come across those terms before. At a briefing earlier today, the two civil servants were good enough to admit that in fact they had made them up. That is perfectly okay, except for one thing—the use of the word “deterrence”. They could just as easily have referred to something like “intermittent deterrence”, “semi-deterrence”, microscopic deterrence” or “virtually zero deterrence”. It is not really deterrence unless it is certain; that is why it used to be called “mutually assured destruction”. It is not enough to be able to threaten destruction; it has to be assured because otherwise the person may not be deterred.

It may seem as though the Liberals’ policy is in disarray, but they could still emerge, at the end of this process, as the winners. I will explain why. At the next general election, we could have another hung Parliament, as my hon. Friend the Member for Plymouth, Sutton and Devonport (Oliver Colvile) suggested. The Liberal Democrats could then say to the Leader of the Opposition, “All that stands between you and entering No. 10 Downing street is to get rid of this weapons system.” They would not say, “Go down to two boats”; they would say, “Get rid of it completely”, because that is what they have wanted all along.

In the unlikely scenario that the hon. Gentleman paints of our having another hung Parliament, the Liberal Democrats would presumably negotiate both with his party and with mine. I think he is going to give me a firm view of what the answer would be from his party, and our Front Benchers have already given a firm view of what the answer would be from our party.

I am delighted by that intervention, because it not only gives me an extra minute but anticipates the next part of my argument.

If the Leader of the Opposition accepted that deal, then knowing the Liberal Democrats, they would start making the same offer to the current Prime Minister, who would have to think to himself, “Well, if I say no and the leader of the Labour party has said yes, Trident is doomed anyway, so I may as well say yes as well.” Who knows how these things might work out?

However, a solution is at hand: we could sign the main-gate contracts for some or all of the submarines in advance of the next general election. The only reason we put that off was to enable the Liberal Democrats to have their alternative study. They have had their alternative study, and it did not even consider a two-boat solution; it considered only a three-boat or four-boat solution. It could hardly be a breach of the coalition agreement if we were to challenge the Liberal Democrats to accept signing the contracts on the first two boats, if not the first three. That would at least prevent them from blackmailing either party, in the event of a hung Parliament, to get rid of the deterrent entirely.

At the most recent Defence questions I think I heard from the Opposition a commitment to try to bring forward the main-gate decision to this side of the election. I urge Opposition Members who believe in deterrence to join Conservative Members and put relentless pressure on our leaders for a grand coalition to bring forward the main-gate decision and secure the future of the nuclear deterrent—

I want to shift the terms of the debate. I do not want to pursue the fallacy of an independent deterrent, although let us be very clear that it is a fallacy: our so-called nuclear deterrent is not independent—we would need agreement from the US to do almost anything with it—and there is not very much evidence that it is a deterrent, either.

I want to make some progress.

Rather than pursuing that particular argument, I want to argue that it is now time to shift the emphasis of the defence debate and that the best deterrence of all is to work with other nations to solve global threats such as fossil fuel-induced climate disruption, transnational trafficking of weapons and drugs, and the poverty and desperation that fuel conflict, hunger and violence around the world.

That is why it is deeply worrying and, indeed, the height of irresponsibility that both the 2010 strategic defence and security review and this review of an alternative to Trident have not explored the full range of options. The Prime Minister trumpeted the review as “neutral” and “factual”, but I would argue that it is biased and empty of essential facts. That means that there is a risk that any parliamentary votes taken in 2016 will be ill-informed and hung up on a cold war era that has long gone.

The decision that should be taken is one based on what would genuinely contribute most to the security of the British people. There is a real argument that says that by not replacing Trident we could improve national security and allow the Ministry of Defence to spend the more than £100 billion saved over the lifetime of any successor nuclear weapon system on an appropriate response to the real security threats and challenges of the 21st century. The 2010 national security strategy identified these as organised crime, cyber-warfare, pandemics and, of course, climate change. Scientists, former US Presidents and, indeed, former UK Prime Ministers, among others, have all agreed that climate change is in fact the greatest threat facing humankind, and every pound spent on Trident is a pound not spent on more appropriate responses to the real dangers linked to climate change.

If that is the case, let us explore how that money could have been better spent. The £80 billion to £100 billion price tag for Trident could have been spent on energy efficiency, energy conservation and renewable energy, all of which represent an investment in a positive future and the opportunity to be world leaders in an area of rapidly advancing technology, as opposed to a cold war past. Just £16 billion would insulate the 16 million homes in Britain that are currently uninsulated, saving 4% of UK carbon emissions and helping to prevent 20,000 annual cold-related deaths, and £30 billion would provide 3,500 offshore turbines, supplying 15% of UK electricity use. Crucially, positive investment in a greener future would make us more secure by reducing the impacts of climate change and ending our dependence on foreign oil—a key root cause of global terrorism.

The national security strategy also highlights the ongoing need to tackle terrorism, but as Tony Blair himself said in October 2005:

“I do not think that anyone pretends that the independent nuclear deterrent is a defence against terrorism”.—[Official Report, 19 October 2005; Vol. 437, c. 841.]

A group of senior military officers, including the former head of the armed forces, Field Marshall Lord Bramall, reached much the same conclusion in a letter to The Times in 2009:

“Nuclear weapons have shown themselves to be completely useless as a deterrent to the threats and scale of the violence we currently face or are likely to face, particularly international terrorism.”

As one commentator has recently put it,

“confronting the threats of today with nuclear weapons is as archaic as attempting to fight tanks with a blade attached to the barrel of a rifle would have been 70 years ago.”

The bottom line is that the UK does not need Trident; nor can we afford it. An independent and strategic assessment of risk does not justify spending tens of billions of pounds on Trident when we have, for example, troops on the front line who are not getting the equipment they need. Alternatively, and in this time of austerity, we might also question whether or not the initial estimated £25 billion could pay instead for 60,000 newly qualified nurses or 60,000 new secondary school teachers for the next 10 years. That is why I say that to use the amount of money suggested on a project that will make Britain and the world less, not more, safe is politically irresponsible, morally bankrupt and economically obscene.

Moreover, this Government, like the last, have committed themselves under the non-proliferation treaty to

“make special efforts to establish the necessary framework to achieve and maintain a world without nuclear weapons.”

The UK committed to multilateral disarmament when it signed the NPT in 1968 and agreed to negotiate the elimination of all nuclear weapons. So far, Britain has not played a particularly constructive role in that process.

Let me give an example. When 132 states gathered in Oslo in early 2013 to discuss the humanitarian impact of nuclear weapons, the British Government were not even there. Replacing the Trident system means committing the UK to maintaining an arsenal of nuclear weapons for decades to come. Expert opinion indicates that that is not in line with the UK’s obligations as an NPT signatory to pursue negotiations in good faith on nuclear disarmament.

I cannot answer for the present Government, but it is a matter of fact that the last Labour Government reduced the number of warheads and got rid of the WE177 freefall bomb, so it is not true to say that the Labour Government did not make moves to reduce our nuclear weapons arsenal.

What I said was that Britain has so far not played a particularly constructive role in the process. I have described what happened in Oslo earlier this year. Irrespective of the firepower, the message that we are sending to other states is that the way to be secure is to get more nuclear weapons. That is likely to make us less safe, not more safe. I do not know how we will be able to argue that Iran should not get nuclear weapons, as I deeply hope it will not, if we are perceived to be enhancing our nuclear weapons.

No I will not, because I have more to say.

Moral and diplomatic leadership is required in multilateral disarmament initiatives such as the global nuclear abolition treaty and the UN’s proposed weapons of mass destruction free zone in the middle east. How can the UK participate constructively in multilateral negotiations on a treaty to ban and eliminate nuclear weapons when it is perceived to be doing the opposite at home?

Moreover, if we keep and upgrade our nuclear weapons, we will send a signal to countries in the rest of the world that they should go out and get nuclear weapons as well. Remaining nuclear-armed for at least another half century will encourage other states to take the nuclear road and ensure that we face the very threats in decades to come that we least want to see. As Kofi Annan has put it:

“The more that those states that already have”

nuclear weapons

“increase their arsenals, or insist that such weapons are essential to their national security, the more other states feel that they too must have them for their security.”

The more countries there are that have nuclear weapons, the more risk there is that they will be used. We cannot preach non-proliferation to countries such as Iran and expect it with any conviction while we are perceived to be maintaining and increasing our own arsenal. It is a very odd insurance policy that makes us less safe, not more. For those who are worried about our status in the international community if we do not have Trident to sit astride, Dr Hans Blix, the former UN weapons inspector, points out:

“Japan and Germany seem respected even without nuclear weapons.”

In conclusion, the economics, the evidence and the ethics all point in one direction. What happens next is a game changer, because any decision about the future of Trident will shape the future that we face. I believe that we need to show leadership and courage. We are on the brink of committing a huge amount of money to a system that might well make us less safe, not more. The signal that it will send to the international community is that the way to be safe is to acquire more nuclear weapons. As more countries do that, our own security will be further undermined. That is why we ought to use this historic opportunity to begin seriously the effort of disarmament by not replacing Trident and by using the money in a far more creative way.

I pay tribute to my hon. Friend the Member for North Devon (Sir Nick Harvey), who was a very good and collegiate colleague in the Ministry of Defence. I am sorry that he was not able fully to carry out this work, because had he done so, I suspect the result would have been a lot better than this inadequate document that has been presented to the country today. It has taken two years to produce what has amounted to a mouse.

It is important that we remember the context. In 2009, the leader of the Liberal Democrat party, who is now the Deputy Prime Minister, said in this House that

“we should admit that we neither need nor can afford to replace Trident.”—[Official Report, 1 July 2009; Vol. 495, c. 297.]

That is where the Liberal Democrat party was a few years ago. It now appears to agree that we should continue with the deterrent, albeit on a part-time basis. However, this is not the end of the story. This is not the party’s defined position. The document does not represent the settled policy of the Liberal Democrats. That is to be settled by their whacky members at their party conference later this year. Therefore, whatever is said from the Dispatch Box, or by Liberal Democrat Members, is not the final word on this matter of huge importance. One thing that can be said of the document is that at least it has sparked this important debate, which has produced some extremely impressive speeches that I hope will gain wider currency across the country.

I wish to make three points. First, the deterrent has deterred. It has worked. We therefore do not need to invite people to make an act of faith.

I listened carefully to the honest and courageous speech by the hon. Member for Brighton, Pavilion (Caroline Lucas), in which she said that the more countries that have nuclear weapons, the more likely it is that they will be used. Does my hon. Friend agree that the only time nuclear weapons have been used was when only one country had them, and that as more countries have acquired them the likelihood of their being used has decreased? No nuclear weapon has been used since more than two countries have had nuclear weapons. Does that not tell us something?

It does, but, if I may, I will come on to my hon. Friend’s point in a moment.

My second point is that, yes, the deterrent has worked and it worked during the cold war. The argument is that the cold war has ended and so we no longer need the deterrent. However, as my right hon. Friend the Member for North Somerset (Dr Fox) said, we cannot predict what threats we might face in the next 30 or 40 years. While there appears today to be no immediate nuclear threat to our country, we know that other countries either have, or intend to acquire, a nuclear capability, and that there are approximately 17,000 nuclear weapons in existence.

If the hon. Lady will forgive me, I, too, have quite a lot to say. If she will permit me to continue to make my argument, this is an important point.

In 2010, the Ministry of Defence’s Development, Concepts and Doctrine Centre published an updated version of Global Strategic Trends to 2040. On nuclear weapons and the proliferation of nuclear capabilities, its report noted:

“The likelihood of nuclear weapons usage will increase.”

Notwithstanding what my hon. Friend the Member for Harwich and North Essex (Mr Jenkin) said, that is the view of the centre. It stated:

“Nuclear proliferation will be a significant factor affecting global security, especially as the transition to a multi-polar distribution of power brings change and uncertainty.”

Given those circumstances, my third point is that in the face of such analysis it would be a dereliction of duty to render our people vulnerable, and the Liberal Democrats are proposing to gamble with the security of Britain. I refer to paragraph 32 of their review. In respect of the alternatives cited, it states:

“The analysis has shown that there are alternatives to Trident that would enable the UK to be capable of inflicting significant damage such that most potential adversaries around the world would be deterred.”

It goes on to say:

“None of these alternative systems and postures offers the same degree of resilience as the current posture of Continuous at Sea Deterrence, nor could they guarantee a prompt response in all circumstances.”

When the Chief Secretary to the Treasury says that his proposal would deter most potential aggressors, he owes it to us to tell us who the aggressors are who would not be deterred. We need to know the answer to that.

The case tonight has been made overwhelmingly. I would like to add an ancillary benefit to the main thrust of the purpose of the deterrent. It was alluded to by my hon. Friend the Member for Plymouth, Sutton and Devonport (Oliver Colvile) when he said that the possession of this deterrent conferred upon the United Kingdom an important degree of influence in the world. It gives us enormous respect with the United States of America, and although that alliance might not be important to the hon. Member for Brighton, Pavilion (Caroline Lucas), it is important to the rest of us. It is important, therefore, that we recognise these ancillary benefits, which confer important influence on the UK.

I agree with my hon. Friend the Member for New Forest East (Dr Lewis) that with all the cross-party agreement between the Opposition and ourselves, we should proceed as early as possible to ensure that the security of the United Kingdom is put beyond doubt and bring main-gate forward.

I am pleased we are having this debate and that the hon. Member for New Forest East (Dr Lewis) has spoken, because he sincerely believes in nuclear weapons as much as I sincerely disbelieve in them. Interestingly, he quoted Tizard as one of the main scientists involved in the Manhattan project and the development of nuclear weapons, but we should also recall that many of the others involved, including Joseph Rotblat and Einstein himself, were later appalled at what they had discovered, at how it had been used and at the consequences for humanity of possessing nuclear weapons at all.

I hope that the hon. Member for Brighton, Pavilion (Caroline Lucas), I and one or two others might manage to bring to the Floor of the House a sense that there are alternatives to Trident. The review that the Liberal Democrats have asked for and that was no doubt produced at enormous expense is not a discussion of the alternatives. It is a discussion of weaponry and, in part, of perceptions of security and risk, but it is not a discussion of the alternative to Trident and nuclear weapons, which is not to have them at all and instead to aspire to a nuclear-free world. Interestingly, when those who support nuclear weapons are challenged, they all say they want to live in a nuclear-free world—

Not all of them. I beg the hon. Gentleman’s pardon. I exempt him from my last remark. He wants to live in a nuclear world, but many who agree with him about the decision on Trident want to live in a nuclear-free world, yet they go on to say that they cannot do anything about it, because now is not the time to do it, and then they head off rapidly down the road of weaponry and cold war attitudes towards deterrence and defence.

One or two fundamental questions need to be asked. A nuclear weapon is not a targeted weapon. Let us imagine we set off a nuclear weapon against, say, France. Let us suppose a Conservative Government got very angry with President Hollande. They are frequently angry with the French on most matters. They have never quite forgiven them for the 100 years war or the French revolution—[Interruption.] See, they are cheering up now. They are licking their lips at the prospect of war with France. Indeed, this whole building is festooned with memorabilia about the French revolution and the defeat of Napoleon. If they wanted to teach the French a lesson by sending a nuclear weapon against them, it would not take out a military establishment or an airport; it would take out millions of people in the civilian population, just as it would if used against Moscow, Pyongyang, Tehran or anywhere else. A nuclear weapon is a weapon of indiscriminate mass destruction against a civilian population. Small nuclear weapons were used in 1945 over Hiroshima and Nagasaki. They were tiny in comparison with one warhead on one part of a Trident submarine now, and the cancers from those weapons have existed and lasted for 60 years. The use of a nuclear weapon sets off a nuclear winter and an environmental disaster for those affected.

To those who want us to spend, in reality, £100 billion on Trident, I say that by 2020—if the main-gate decision is taken in 2016—a large proportion of the defence budget will be taken up in building new submarines and the warheads to accommodate them. Will defence chiefs at that time accept cuts in every other area of defence expenditure to accommodate the construction of those new submarines and new missile systems? I seriously doubt it. Those in the House who talk so glibly about nuclear weapons know full well that there is a serious debate in the Royal United Services Institute and the defence establishment about targeting defence expenditure on nuclear weapons when so many other demands are apparently being put forward by different service chiefs.

To my colleagues in the Labour party, who have been through this debate on nuclear weapons many times, I say that if we win an election in 2015—obviously, I hope we do—the demands on that incoming Government about apprenticeships, student fees, benefits, hospitals, schools, council housing, railways, roads, and a whole range of things, will be massive. Will we say to our supporters, “Sorry, the priority is weapons of mass destruction. The priority is nuclear weapons”? I like to think we would not.

Yes, we face threats in this world, including from terrorists, but holding nuclear weapons did not do the USA much good on 9/11, or us much good on 7/7, and it has not done anybody else much good. We must look to the causes and the humanitarian effects of war. A 1996 International Court of Justice ruling stated that

“the threat or use of nuclear weapons would be generally contrary to the rules of international law applicable in armed conflict, and in particular the principles and rules of humanitarian law.”

Let us look for alternatives such as nuclear weapon-free zones, supporting a non-proliferation treaty, or a conference of middle eastern states to bring about a nuclear weapon-free middle east. The review is not an alternative document but one that leads us down the road of nuclear proliferation and danger. The real alternative, produced by the Campaign for Nuclear Disarmament, sets out an agenda for peace and investment in people, jobs and a good future for this country, not investing in weapons of mass destruction.

I hope I have managed at least to bring an alternative view to this debate.

I first stopped and thought seriously about nuclear weapons and the issues associated with them 30 years ago after I spent some time in the forest near a little town called Menden in West Germany. I was there with 50 Missile Regiment, which had battlefield nuclear weapons—we do not have those any more. The purpose of that regiment, come war time, was to fire its Lance missile into Soviet tank configurations, possibly in a battlefield context as a first-strike weapon. The regiment had three missiles, but it only ever trained to use one because its signature would have been picked up and the regiment would have been wiped out by Soviet battlefield nuclear weapons before it had even got close to loading the second missile. Its members did not bother practising to drive away either, as they had worked out that they could not get away fast enough to get out of the impact area of the weapon that would be fired against them. I have no doubt that the regiment would have been prepared to fire its weapon, and it was a sobering experience.

A few years later in the Army I was tasked with lecturing and explaining the consequences of using intercontinental nuclear weapons, and I had to learn the difference between the consequences of using ground-burst weapons—those have been replicated on television and people might have seen the force that moves out along the ground—and air-burst weapons. Ground-burst weapons are appalling, but the consequence of air-burst nuclear weapons is truly horrific by comparison. I learned two lessons from those experiences. First, that such weapons are the worst example of man’s ability to cause death and destruction, and secondly that this country must never be exposed to those who believe they could use such weapons against us with impunity.

I realise that over the years others have taken a different stance, and have done so in a principled way—I am thinking of previous Labour party leaders who had an open and sincere belief that they expressed during the 1980s. They were wrong: the SS-20s did not disappear from the Ural mountains because well-meaning people danced around Greenham Common air base but because cruise missiles were put into Greenham Common air base.

I understand, too, that for some the idea of putting country before party is difficult. I understand that when coalition offers an opportunity for power, their approach might well be that party policies are paramount and not what is best for the United Kingdom. It is unfortunate when that happens, not least because it leads to a large amount of expenditure of time and money on reports such as the one we have been considering over the past couple of days. Commissioning a report in the false hope that it would undermine the argument for a submarine-based nuclear deterrent was always going to fail. Russia is not modernising its submarine fleet for no good reason and China is not expanding its submarine programme on a whim.

The report is published and confirms that the only viable option is the submarine-based system, but what comes next, sadly, is the most appalling piece of “party before country” politics that I can recollect. The analysis of my coalition partners seems to be, “Our report has confirmed that the submarine system is the only option. It is the only option because it provides an effective continuous deterrent, so we will therefore go with the submarine system, but seek to make it non-continuous and therefore less effective and seek to portray that as progress.” If the Chief Secretary is a unilateralist, he should have the moral courage to come out and say so. If he is not, he should realise that this idea ranks somewhere between third rate and poor. The “four boat, continuously at sea” policy is the only practical way to maintain the effective deterrent that has protected these islands for a long time. It is about time we got on with its modernisation.

Political maturity and national interest should dictate that coalition partners now accept that the part of the agreement that delays matters to 2016 has been rendered obsolete by this report and that a positive decision can and should be brought forward.

Sometimes, we have to be blunt with the public and tell them what we are talking about when it comes to the nuclear deterrent. We are talking about what stops war, and it is a question of unacceptable loss and reaching a point where the losses from fighting are so great that one cannot contemplate moving forward.

It is important and necessary for aggressors to believe that the UK has the capability and the resolve to deliver unacceptable losses in response to an imminent attack. We have thrown around lots of words tonight in this debate, but for me the most important has been credibility. Credibility is what the debate must be about. How credible are the threats out there that we face? How credible is our nuclear deterrent capability to our allies? How credible is our deterrent to our potential enemies?

We have been told that this has been a comprehensive review and analysis, but I cannot believe that. I have read the document and, like many right hon. and hon. Members, I found little in it of substance. The hon. Member for North Devon (Sir Nick Harvey) said that the nature and scale of the threat are no longer the same as they were during the cold war. He also, I believe, said we were not facing a tier 1 threat, but the national security strategy highlights the risk of nuclear attack under two tiers: tier 1, which is international terrorism including a nuclear attack by terrorists; and tier 2, which is an attack by a state proxy using chemical, biological, radiological or nuclear material.

We need to look at the credibility of the threat. On Iran, the director general of the International Atomic Energy Agency said in his report to the board in June 2013:

“As my report on safeguards implementation in Iran shows, the Agency continues to verify the non-diversion of nuclear material declared by Iran under its Safeguards Agreement. However, Iran is not providing the necessary cooperation to enable us to provide credible assurance about the absence of undeclared nuclear material and activities. The Agency therefore cannot conclude that all nuclear material in Iran is in peaceful activities.”

Iran remains a credible threat.

Turning to Pakistan, the Stockholm International Peace Research Institute confirmed in 2011 that Pakistan had increased its total number of warheads from between 70 and 90 in 2010 to between 90 and 110 in 2011. The risks of instability in its relationship with India and of the spread of its technology and expertise to other nations have to be a great concern.

North Korea is increasingly unstable. Earlier this year we saw an increase in tension and we cannot begin to contemplate what that Government would see as an acceptable thing to do.

Is there a credible threat of nuclear terrorist attack from non-state actors? According to Barack Obama in 2010:

“The single biggest threat to US security, both short-term, medium-term and long-term, would be the possibility of a terrorist organisation obtaining a nuclear weapon.”

Last week my hon. Friend the Member for York Central (Hugh Bayley) and I were in Washington as part of a NATO delegation, meeting people from the Pentagon, the State Department and a number of think-tanks. I have also talked to NATO partners about the UK’s nuclear capability, and I asked them what their views would be if the UK removed, or failed to replace, its continuous-at-sea deterrent or CASD. With the exception of only one country, they reacted with horror. I cannot begin to contemplate what the US would think in terms of its pivot to Asia if Europe’s nuclear deterrent were downgraded. It is already concerned at Europe’s inability to meet the 2% budget commitment for support to NATO, yet in this report we are contemplating downgrading our nuclear deterrent. NATO is involved in collective defence and it is a nuclear alliance, yet here we are talking about removing some of that nuclear deterrent.

Finally, there is the issue of the credibility of the deterrent. None of the alternative systems and postures offered in this review offers the same degree of resilience as the current posture of CASD, nor could they guarantee a prompt response in all circumstances. We just cannot move away from that one statement. That says it all. The risk this review finds we would face is unacceptable. It has to be unacceptable in respect of the safety and security of this country, our role and responsibilities within NATO and our role and responsibility to work towards world peace through that nuclear alliance.

I will confine my remarks to just a few points. I congratulate the hon. Member for Bridgend (Mrs Moon) on bringing out the NATO side of the debate. Our continuous-at-sea deterrence is an important contribution to NATO. It is a pay-back to the United States for being the ultimate guarantor of European security. We should not imagine for a minute that if we started downgrading our deterrent, the United States would remain as interested as it is now in maintaining security in Europe, with all the benefit for this country.

This debate has demolished the credibility of the document. The idea that it came as a surprise that submarine-launched cruise missiles with new nuclear tips were going to be fantastically expensive represents a scale of political dishonesty that stretches the imagination even for Liberal Democrats. I cannot imagine how anybody has ever taken the document seriously.

The debate has essentially been about continuous-at-sea deterrence or not. The document damns the idea of a part-time deterrent. Paragraph 33 states that a non-continuous posture depends upon political confidence that

“a potential aggressor would not launch a no-notice pre-emptive attack”—

there is no guarantee of that;

“with sufficient warning, the UK could re-constitute back-to-back patrolling”—

there is no guarantee of that;

“such back-to-back patrols could then be sustained long enough to cover any emergent crisis”—

and there is no guarantee of that if we have only three or two boats.

The point that I wish to make briefly is what defence policy is really about. It is not about predicting the future and working out what we might use. It is not about pretending that we can assess threats and that then settles what we need for the future. The whole point about defence planning and defence policy is that it is about preparing for what we do not expect, making contingencies for what we cannot foresee. That is what the whole document fails to do. The idea that we now live in a different world from the one we lived in during the cold war, and therefore that the global environment has given us permission to downgrade our nuclear capability, is clearly nonsense.

There is another misunderstanding. This is not a weapons system that we have not used, do not use and are unlikely to use. The importance of our continuous-at-sea deterrent is that we use it every day. It shapes the global environment in which we live. Why is state-on-state warfare a second-tier threat rather than a primary threat? Why has state-on-state warfare between the major powers become unthinkable since the end of the first half of the 20th century? It is because those major powers have nuclear weapons. Were we to start destabilising the credibility of our continuous-at-sea deterrence, we would be destabilising the very global environment that the Liberal Democrats believe gives them permission to go part-time on our deterrent. My hon. Friend the Member for Aldershot (Sir Gerald Howarth) put it well. The part-time deterrent is no deterrent. We might as well pack it in unless we are going to stick with continuous at-sea deterrent.

I am conscious of the expertise that has been demonstrated in the House today. Although I have much respect for the Chief Secretary, I would not include him in that after today’s performance. His body language today suggested somebody who was well out of his comfort zone. He missed much of the debate, which was exceptionally good. The debate was about continuous-at-sea deterrence. It is a good job that it was not about continuous-at-Chamber attendance, because the Chief Secretary scurried out of the Chamber after only the second speech. He was quoted as saying that the Army has more horses than tanks so there is plenty of room for defence savings. This does not reflect a firm grasp of military matters.

Many of us have gone through this journey. I have been influenced by many hon. Members and not least by Franklin Miller, who is an expert on these matters. We have taken the same journey in recognising what is required for continuous-at-sea deterrence. Our deterrence protects us from nuclear coercion, nuclear blackmail and nuclear attack. That is not just for now, but for the lifetime of the vessels, which is way beyond the horizon that the Chamber can predict. The Lib Dems recognise that there is a threat—that is clear—but they want a package that will mean that the UK is vulnerable. It is a part-time deal and proves that matters of security are not safe in their hands.

The “Guinness Book of Records” might one day honour many of us on the Government Benches for the length of time that we have had to grit our teeth and tolerate the coalition, but this latest idea from the Lib Dems is as mad as it is dangerous.

This has been an important debate. I congratulate all Members who have contributed. A number of strong and passionate opinions have been expressed. It is important that all views are heard in this debate. I agree with the hon. Member for Bournemouth East (Mr Ellwood) that it is a shame that the Chief Secretary to the Treasury was not in the Chamber to listen to the debate. Indeed, I think it was quite discourteous of him to leave his ministerial colleagues from the Conservative party to listen to the debate on their own.

I pay tribute at the outset to the men and women serving in our forces, in particular—in the light of this evening’s debate—the Royal Navy and staff based at Clyde naval base, who work with the deterrent day in, day out. It is somewhat questionable that the Member representing them—the hon. Member for Argyll and Bute (Mr Reid)—chose not to speak in today’s debate. However, many of those men and women are my constituents. I also pay tribute to the civilian and the industrial work force who support the operation. We are all—

I am sorry; I do not have time to. [Interruption.] The hon. Gentleman could have put in to speak and he chose not to.

We are all aware of the important job that the Barrow work force do. [Interruption.] The Chief Secretary has no business calling me discourteous; I have been in the Chamber for the entire debate and he has not. I pay tribute to my hon. Friend the Member for Barrow and Furness (John Woodcock) for speaking up so assiduously for his constituents, but there are companies and workers throughout the UK supply chain who are also integral to the success of the deterrent. I also pay tribute to the naval families who are without their loved ones, sometimes for a very lengthy period, with limited or no contact. It is not an easy position to be in. They, too, deserve our support and recognition.

We live in an uncertain and unpredictable world, as I am sure all hon. Members would agree. New threats emerge, but that is not to say that the traditional threats have disappeared. In response, we must have an equipment programme that enables us to deter, detect and tackle the entire spectrum of threats that we face as a nation. We on the Labour Benches are committed to the minimum, credible independent nuclear deterrent, which we believe is best delivered, both in effectiveness and cost, through a continuous-at-sea deterrent. We have rightly been keen to scrutinise the report on the grounds of capability, cost and disarmament, but absolutely nothing in it suggests that it would be in the UK’s interests to move away from a CASD.

We have heard from some Members that our deterrent is nothing more than a legacy of the cold war. Of course, the old divisions of the cold war have passed, but they have been replaced with new uncertainties. Indeed, the hon. Member for Plymouth, Sutton and Devonport (Oliver Colvile) and my hon. Friend the Member for Dunfermline and West Fife (Thomas Docherty) outlined those threats, which are real. They are not imaginary or historic; they are very much present. We cannot predict what will happen. It is this age of uncertainty that is one of the driving reasons why it would be foolish to give up our deterrent now. Important points on that were made by the hon. Members for New Forest East (Dr Lewis) and for Harwich and North Essex (Mr Jenkin).

We support a policy of multilateral disarmament. Like many speakers in the debate, I want to see a world free of nuclear weapons. It should be a cross-party priority for the UK to continue on the path towards multilateral nuclear disarmament, alongside our international allies, as a signatory of the non-proliferation treaty. The last Labour Government made progress towards that, as we have heard. I know that work is ongoing to reduce the number of warheads further. I am sure that we would all appreciate some information from the Minister about that.

Those who were expecting the report to be published with some credible alternatives—they included my hon. Friend the Member for Islington North (Jeremy Corbyn)—will be sorely disappointed, as he pointed out. It was all too clear from the Chief Secretary’s opening remarks that the report offers nothing new. In fact, it showed that the Liberal Democrats have taken two years to review a policy and spent thousands of pounds of taxpayers’ money, only to conclude that their past policy simply does not work. In fact, the only thing that we have learned from the report is that the Liberal Democrats are now well and truly a Trident party.

I am not sure whether to feel sorry for the Chief Secretary or to admire him. He has now reversed his party’s long-standing opposition to Trident, and I certainly do not envy him his job at his party conference this year. There is real concern that the review has been nothing more than an exercise in Lib Dem and Conservative party management, paid for by the taxpayer and taking up the valuable time of civil servants. That is no way to run a country, especially in relation to a decision of such great importance.

We have heard a number of excellent contributions on the importance of the continuous-at-sea posture, including from the right hon. Member for North Somerset (Dr Fox), my right hon. Friend the Member for Coventry North East (Mr Ainsworth) and the hon. Members for Portsmouth North (Penny Mordaunt), for Aldershot (Sir Gerald Howarth) and for Dewsbury (Simon Reevell). It is not just the existence of our nuclear deterrent but its continuous nature that is central to our discussions and to the report. The report makes it clear, for those who were under any illusion to the contrary, that the

“highest level of assurance the UK can attain with a single deterrent system is provided by SSBN submarines operating a continuous at sea deterrence posture.”

That has been the basis of our deterrent for more than 40 years: an assurance that our deterrent operates 24/7, 365 days a year. In short, any move away from CASD will result in a reduced capability. If our deterrent is our ultimate insurance policy, it cannot be taken seriously if it is only part time. If that is what the Liberal Democrats are proposing, it will confirm what a lot of us have suspected for a long time—that they cannot be taken seriously either. They seem to want a part-time deterrent, but that simply would not deter anyone.

We should also remember that, although the future of the deterrent is a decision for this House, that decision should not be taken in isolation from the rest of the world. It would appear, however, that the Chief Secretary did not even bother to consult anyone outside Whitehall, let alone in the rest of the UK. As my hon. Friend the Member for Bridgend (Mrs Moon) said, the UK is a proud member of NATO, alongside our international allies, and any decision to switch to an alternative platform, or even to adopt the Lib Dems’ part-time deterrent, would have consequences for NATO. It would indicate a significant change in our approach to defence across the world.

The hon. Member for Moray (Angus Robertson) and I share a desire to see a world free of nuclear weapons, although our views differ on how that would best be achieved. We are looking to work with our international partners to rid the world of nuclear weapons, but his party’s policy is a uniquely insular one—namely, to remove the deterrent from the Clyde and claim victory because it has moved 100 or so miles south. The hon. Gentleman might also want to check his statistics, because the most recent YouGov poll showed that 52% of the Scots surveyed thought that having our own nuclear deterrent was important, with only 38% against that proposal. That is far from the majority against the proposal that he spoke of earlier. Also, given that not a single poll has ever shown a majority of Scots to be in favour of independence, he should be very careful about wanting to carry out public policy by opinion poll.

In fact, the hon. Gentleman led the way for the Chief Secretary to make his U-turn, because the hon. Gentleman U-turned the Scottish National party’s opposition to nuclear weapons by forcing the party conference to adopt a pro-nuclear alliance position, in line with its ambition to join NATO. So he has no credibility on this issue—[Interruption.] And quoting himself is not going to make him any more credible.

Paragraph 32 of the report states:

“None of the alternative systems and postures offers the same degree of resilience as the current posture of Continuous at Sea Deterrence.”

I thank the Chief Secretary for using the report so effectively to make the case for continuous-at-sea deterrence, and I welcome the conversion of his party to supporting the nuclear deterrent. The report sets out very clearly that CASD is the most efficient and cost-effective deterrent, and I hope that we can all now proceed on that basis.

It is a great pleasure to follow the hon. Member for West Dunbartonshire (Gemma Doyle), who spoke with great good humour, particularly in demolishing some of the arguments of the isolationists on this issue.

This has been a most unusual debate on a most a critical subject of the utmost importance to the first duty of Government: defence of the realm. It is unusual, as it reflects a challenge of governing in coalition. This debate in Government time was opened by a Government Minister, my right hon. Friend the Chief Secretary—for whom I have considerable respect, for his day job—who supports one position, and is being closed by another Government Minister who is about to advocate an alternative view.

This difference of view was, of course, anticipated when the coalition came into office. The coalition agreement of May 2010 said:

“We will maintain Britain’s nuclear deterrent, and have agreed that the renewal of Trident should be scrutinised to ensure value for money. Liberal Democrats will continue to make the case for alternatives.”

Later, in the 2010 strategic defence and security review, the Government’s commitment to maintaining a continuous submarine-based deterrent was confirmed and the work of replacing the existing submarines was begun. Yesterday, the Cabinet Office published an unclassified version of the review into Trident alternatives, so the Government have now delivered on their commitment set out in the coalition agreement.

This debate has been remarkable, too, for the quality of contributions from right hon. and hon. Members. Before addressing some of the points raised, I want to make clear a few points of my own.

The UK’s nuclear deterrent exists to prevent, at the extreme, any threat to our national existence or nuclear blackmail from a nuclear-armed state against the UK homeland or our vital interests. We hope never to use nuclear weapons, but to deliver deterrent effect under all foreseeable circumstances. Our ability to do so must be credible and assured at all times, and this depends on there being no doubt in the mind of a potential adversary about our ability and determination to employ our nuclear weapons, if necessary. This has been the judgment of successive Governments since the nuclear age began.

Although I recognise that the cold war is over, I do not recognise the argument advocated by the hon. Member for North Devon (Sir Nick Harvey)—that this allows us to drop our guard against threats that might emerge over the next 50 years. This debate is not about our security today; it is about the security of our children and our children’s children.

No one may like it—least of all the hon. Member for Brighton, Pavilion (Caroline Lucas)—but there remain 17,000 nuclear weapons around the world. Russia is spending $650 billion over 10 years to modernise its armed forces, including upgrading the readiness of its nuclear systems. We live in a time of unprecedented acceleration in the development of nuclear technology and the desire among nations in unstable regions of the world to procure nuclear capability.

I am afraid I do not have time.

Iran has a well-established ballistic missile programme, is looking to extend its range and is close to being capable of developing a nuclear weapon. North Korea has proven nuclear capability and has tested ballistic missiles with increasing range. Only last week, a ship destined for North Korea with missile parts on it was intercepted in the Panama canal. This is a very uncertain world. I for one do not have the confidence to forsake a capability that has served this nation so well these past nearly 50 years in maintaining the security of the nation.

The maintenance of the UK’s deterrent in the face of the clear threat during the cold war and the uncertainties of today’s world has been possible only because of the dedication of those who have worked tirelessly to provide it. I am sure the whole House, regardless of Members’ views on the issue, will join me in paying tribute to the crews of our submarines and their families, and all the men and women, both military and civilian, who are engaged in providing our deterrent. I also wish to take the opportunity to congratulate them on the successful conclusion a few weeks ago of the 100th patrol undertaken by the Vanguard class of submarine under Operation Relentless—a significant achievement and a testament to the commitment, professionalism and skill of all those involved.

As my hon. Friends the Members for Plymouth, Sutton and Devonport (Oliver Colvile) and for Basildon and Billericay (Mr Baron) have requested, I pay tribute to the service of the veterans of British nuclear test programmes whose contribution ensured that the United Kingdom has been equipped with an appropriate deterrent over the past 45 years.

During tonight’s debate, many Members on both sides of the House have commented on the purpose of the Trident alternatives review. That is worth revisiting, because of the context that it provides for the debate and the conclusions of the review.

The Liberal Democrats’ opposition to the renewal of our nuclear deterrent based on the Trident system is well known. In 2007, they voted against the then Government’s decision, set out in the 2006 White Paper, to maintain our nuclear deterrent by building a new class of submarines. In 2009, the leader of the Liberal Democrats said

“we should admit that we neither need nor can afford to replace Trident.”—[Official Report, 1 July 2009; Vol. 495, c. 297.]

In their 2010 general election manifesto, the Liberal Democrats said that they would

“rule out the like-for-like replacement of the Trident nuclear is unaffordable, and Britain's security would be better served by alternatives”.

The Chief Secretary has just confirmed that, as the author of the manifesto, he wrote those words. So the Liberal Democrats’ position was very clear: there would be no replacement of Trident, but they would explore alternative nuclear deterrent systems. As I have said, that position was reflected in the coalition’s programme for government.

I have to say that I feel some sympathy for my right hon. Friend the Chief Secretary. It was no doubt an uncomfortable moment for him when he realised during the course of the review that he would have to come to the House and report that, in fact, there were no cheaper alternatives to our Trident system after all. It must have been even more uncomfortable for him to realise that, instead of being able to stand at the Dispatch Box and make the case for some sort of cruise-missile based system—which, by the way, would offer a far less credible deterrent than Trident—he would have to execute a major U-turn, and accept Trident.

Of course, having been forced by the facts to accept the Trident system for party political reasons—to try to maintain some sort of differentiation on nuclear weapons, and to appease the disarmament wing of the Liberal Democrat membership—the Chief Secretary is now advocating a breaking of the posture that has been the foundation of our deterrence for the past 45 years: continuous-at-sea deterrence.

The Chief Secretary said a good deal about the parameters of the review and the conclusions that it drew, but he missed one vital point of which I am sure the House will want to be aware. Members will no doubt have spotted that paragraph 4 of the Executive Summary of the document states that the review

“does not produce a comparison of like-for-like capability.”

There is a very simple reason for that. The review demonstrates that no alternative system has a capability that is comparable to our continuous-at-sea submarine-based deterrent with Trident missiles. The two former Secretaries of State for Defence, my right hon. Friend the Member for North Somerset (Dr Fox) and the right hon. Member for Coventry North East (Mr Ainsworth), are perhaps better placed than any other Members who have spoken today, given their own reviews, to see that that is clearly the case.

Having listened carefully to the Chief Secretary’s speech and to contributions from the only other Liberal Democrat Member who was prepared to support this position today, I am still completely at a loss as to what the Liberal Democrats’ policy on Trident actually is. After a two-year review that was specifically designed to help them to come up with a policy, they still have not decided whether they are in favour of two or three submarines. At the start of the week, they briefed the national newspapers that they would come out in favour of just two successor submarines. One newspaper reported:

“Mr Alexander has concluded there is no practical alternative to Trident…but he will detail alternatives for downgrading it, making clear the leadership’s preference is for a two-submarine replacement.”

Yesterday, however, it was revealed that the Trident alternatives review did not even examine the option of replacing the current fleet of four Vanguard submarines with just two successor boats. Why not? Because at the outset, when the Liberal Democrats had the opportunity to raise the issues that they wished to be considered in the review, they did not do so. What a shambles. Only the Liberal Democrats could hold a two-year review, brief the newspapers that they are in favour of an option that was not even in the review and then, when the review is published, refuse to confirm whether they are in favour of it or not.

This Government recognise the need to provide our nation’s security in the most efficient and effective way possible. We need a credible deterrence posture, and CASD alone provides that. I welcome the clear confirmation tonight from the official Opposition Front-Bench team of its new commitment to a continuous-at-sea deterrent, which it expects to be delivered by a minimum effective deployment. That was not its position last week, but it is now. If this change in posture or clarification of the official Opposition—

Motion lapsed (Order, this day).