My hon. Friend will be delighted to know that the answer is yes, we are committed to retaining an independent nuclear deterrent based on the Trident missile system. That is why we have continued with the programme to replace the Vanguard class submarines, including placing initial design contracts with BAE Systems.
That is indeed an excellent answer. Given that a part-time nuclear deterrent would be dangerously destabilising, will the Prime Minister confirm that the British Trident successor submarines must and will operate on the basis of continuous at-sea deterrence?
My hon. Friend is absolutely right to raise this issue. One of the key elements of the credibility of our deterrent has been that it is continuously at sea, and the Royal Navy takes immense pride in having been able to deliver that without a break over so many years. I have met some of the crews and visited some of the submarines. What they do is incredibly impressive and I pay tribute to them for the service that they provide. Yes, being continuously at sea is a key part of our deterrent.