Question to the Ministry of Defence:

To ask the Secretary of State for Defence, how many UK nuclear weapons have been withdrawn from operational service as a result of (a) multilateral negotiation and (b) unilateral action since 1985.

The UK has a strong record on nuclear disarmament. Since 1985 the WE 177 and Polaris warheads have been removed from operational service leaving only one type of nuclear warhead in service delivered by the Trident missile system. These withdrawals from operational service have been as a result of unilateral action. As my right hon. Friend the Secretary of State for Defence set out in his Written Ministerial Statement of 20 January 2015 (Official Report, column 4WS) the Government has met its commitment to implement the changes announced in the Strategic Defence and Security Review 2010 to reduce the number of operationally available warheads from fewer than 160 to no more than 120.