To ask the Secretary of State for Defence whether, as part of the programme to develop a successor to the Trident nuclear weapons system, his Department is carrying out any studies into the feasibility of using Astute class submarines as a platform for the launch of nuclear armed cruise missiles. (319193)

No. The 2006 White Paper “The Future of the United Kingdom’s Nuclear Deterrent” (Cm6994) concluded that a submarine launched ballistic missile system was the most cost-effective replacement for our existing nuclear deterrent. Cruise missiles have a number of disadvantages compared to ballistic missiles including smaller range and payload and increased vulnerability, and we are planning to replace the Vanguard class of SSBN by a new “successor” class of ballistic missile submarines.