Nicholas Soames: To ask the Secretary of State for Defence what assessment he has made of the Royal Navy's requirement for (a) numbers and (b) types of submarines to be available for operations in the next 10 years. [90756]

Peter Luff MP; Parliamentary Under-Secretary of State [holding answer 19 January 2012]: The Royal Navy's requirement for submarines was assessed during the strategic defence and security review. Over the next 10 years we plan to maintain a fleet of four Vanguard class ballistic-missile submarines delivering the strategic nuclear deterrent, and a fleet of seven nuclear attack submarines consisting of a mixture of Trafalgar class boats and the new Astute class boats which are replacing them.