By Tim Sculthorpe, Press Association Political Staff

Press Association – 4 September 2013

David Cameron today ''basically agreed'' with a Tory backbencher who claimed contracts for two new Trident submarines should be signed before the election to avoid being ''blackmailed'' by the Liberal Democrats in any future coalition negotiations.

Julian Lewis (New Forest East) said the Lib Dems' review of Trident alternatives had produced no viable options for a nuclear deterrent, so the Prime Minister should bring forward the ''main gate'' decision and sign deals for the first two of four new subs. He said the deal would stop ''blackmail'' by the Lib Dems in the event of another hung parliament. Mr Lewis has raised the issue of renewing Trident repeatedly with ministers since the alternatives review was published earlier this year.

Answering at Prime Minister's Questions, Mr Cameron said:

''I have to credit you with remarkable consistency on this issue, on which I basically agree with you.

''We have Trident, it is the right approach and we need to renew Trident.

''Actually the delay of the main gate decision has saved us money rather than cost us money. Your point about the review is absolutely right, it shows that if you want to have a proper functioning deterrent then you need to have the best.

''That means a permanently at sea, submarine-based alternative. That is what a Conservative-only government after the next election will deliver.''

Mr Lewis said:

''It costs the Ministry of Defence £1.4 billion to extend the life of the four Trident submarines in order that the Liberal Democrats could have a study of alternatives.

''Now that study has shown there is no alternative to Trident, will you consider signing the main gate contract for the first two submarines so we can never again be blackmailed by the Liberal Democrats in a hung parliament?''