Dr Julian Lewis: My right hon. Friend has just made that commitment to continuous at-sea deterrence and, as I understand, it is the position of both main parties that the successor submarines for Trident should go ahead. Will he therefore guarantee to me that there will be no question of any delay in signing the main-gate contracts if we end up with another hung Parliament and the Liberal Democrats or Scottish nationalists seek to exact that as a price for their participation and support?

[The Secretary of State for Defence (Michael Fallon): I confirm to my hon. Friend and to the House that the main-gate decision is scheduled for 2016. I will not speculate on the possibility of a hung Parliament, except to note that I know the Liberal Democrats would favour some kind of part-time deterrent, although it is pretty obvious to me that our enemies are not part time.]