The programme for implementing the reductions in the number of UK nuclear warheads, as announced in the Strategic Defence and Security Review (SDSR), has commenced, Defence Secretary Dr Liam Fox announced today.
As part of his statement on the SDSR on 19 October 2010 Prime Minister David Cameron said that the Government had reviewed the UK's deterrence requirements and concluded that the requirement could be met for an effective and credible deterrent with a smaller nuclear weapons capability.
Mr Cameron said that over the next few years the current deployed capability would be reduced in scale and this reduction would be incorporated into plans for the successor submarine.
Therefore the number of warheads on board each submarine would be reduced from a maximum of 48 to a maximum of 40, the number of operational missiles on the Vanguard Class submarines would be reduced to no more than eight, and the number of operational warheads reduced from fewer than 160 to no more than 120.
Dr Fox in a written ministerial statement said today:
"I wish to inform the House that the programme for implementing the SDSR warhead reductions has commenced: at least one of the Vanguard Class ballistic missile submarines [SSBN] now carries a maximum of 40 nuclear warheads.
"The programme of work to complete these changes across the Vanguard SSBN fleet will be completed within the constraints of the deterrent's operational programme. We currently expect completion to be made within this Parliament.
"The Government does not comment upon the operational programme and therefore ongoing updates on this implementation programme will not be given.
"I will update the House further once the changes have been completed across the current SSBN fleet and the SDSR commitment to reducing our stock of operationally deployed warheads has been fulfilled.
"On current plans our expectation is that the subsequent reduction in our total stockpile to no more than 180 warheads will complete by the mid-2020s.
"The early commencement of the programme for these reductions in warheads is a significant step and further demonstrates the Government's commitment to fulfilling the UK's disarmament obligations under the Nuclear Non-Proliferation Treaty.
"The Government remains committed to maintaining the minimum credible deterrent necessary to achieve our deterrence objectives of guaranteeing national security."