By David Maddox

Scotland on Sunday – 21 July 2013

A cross-party group of MPs is to launch a campaign to force the UK government to sign the contract for the replacement Trident submarines before the next election. The campaign group, which is currently led by Tory backbenchers, fears that if the contract date is postponed until 2016 then Britain's independent nuclear deterrent could become the casualty of future coalition negotiations after the 2015 general election.

While the MPs will be trying to use their influence in parliament to persuade Prime Minister David Cameron to sign the contracts for the replacement submarines by 2014, Scotland on Sunday understands that a PR company has been approached to launch a public campaign. Part of the strategy will be to woo support in Scotland as the nuclear deterrent is based at Faslane on the Clyde and supports around 9,000 Scottish jobs.

The decision to launch a campaign follows the publication of a Lib Dem government document examining the options on the future of Britain's nuclear deterrent and a suggestion by Treasury chief secretary Danny Alexander that there may only be a need for two new subs – instead of the present four – ending the continuous seaborne deterrent.

The leader of the campaign, Tory New Forest MP Dr Julian Lewis, said that there is now no reason to delay a decision on replacing Trident. Insisting that the campaign has cross-party support, he pointed out that Labour shadow defence minister Kevan Jones had recently challenged Defence Secretary Philip Hammond to bring forward the decision to build the new generation submarines. He said:

"The only reason why the decision was delayed was so the Lib Dems could have their review. Now we have had it, there is no reason to delay further. We can certainly put down an order for two or three of the four submarines and get on with replacing Trident. What was interesting is that even the Lib Dems admitted that the new version of Trident is the only option."

 But he added:

"What should be of great concern is that despite what they said this week the Lib Dems clearly want us to drop our nuclear deterrent. It is imperative that we sign the contract before the next election because if we end up with another hung parliament the Lib Dems will blackmail either my party or Labour into dropping the replacement of Trident."

The review was ordered by Cameron and the Lib Dem leader Nick Clegg, reflecting the Lib Dems' wish to find a cheaper alternative to the ageing submarines ...

[For later developments, click here.]