Image caption The new Royal Navy aircraft carriers are expected to cost £5bn

Contracts worth about £1.25bn have been awarded for building two aircraft carriers even though the project may not go ahead, figures have revealed.

The figures came in answer to a parliamentary question by a Labour MP.

It emerged on Wednesday that the £5bn project to build HMS Queen Elizabeth and HMS Prince of Wales on the Clyde, at Rosyth in Fife, in Appledore, Devon, and Portsmouth could be under threat.

The Treasury said it would announce a decision on 20 October.

The Ministry of Defence is under pressure to cut its budget by a fifth.

The figures - which were obtained by Thomas Docherty, Labour MP for Dunfermline and West Fife - show that more than 100 contracts have already been awarded to companies across the UK.

Mr Docherty, who represents the Rosyth dockyard, said: "These figures highlight that the carrier contracts don't just affect thousands of jobs here in Rosyth and on the Clyde or indeed just across Scotland, but in fact across the whole of the United Kingdom.

"To rip up these contracts worth millions at this stage would not only be financial madness, but political suicide and I hope the coalition government sees sense."

Media playback is unsupported on your device Media caption Thomas Docherty MP on "unreasonable cuts to defence budget"

Shadow Scottish secretary Jim Murphy, also Labour MP for East Renfrewshire, said cancelling the contracts would not only "sink the prospects of thousands of families across the UK" but result in the loss of technical skills "that are so vital for this country".

"In an uncertain world, we need the flexibility the carriers offer to project our naval and military power around the world," he said.

The Chief Secretary to the Treasury, Danny Alexander, told Sky News's Sunday Live With Adam Boulton: "They [the public] have a right to know and they will know when we've made those decisions.

"We'll announce them on October the 20th when we'll set out the picture for public spending - and they'll know too how we're promoting fairness through the spending review.

"That's a piece of work that is going on at the moment and I can't get into commenting on individual items when those decisions simply haven't been made."

The new figures were released as Labour's team in Govan launched a petition - organised by MSP candidate Stephen Curran and Ian Davidson, Labour MP for Glasgow South West - calling on the Ministry Of Defence to end speculation around the carriers.

Image caption Sir Richard Dannatt raised fears over the 80 Joint Strike Fighters due to operate from the carriers.

On Wednesday, BAE systems chief executive Sir Ian King told the Defence Select Committee in the Commons the company had been asked to consider a number of options ranging from "one carrier to no carriers".

But General Sir Richard Dannatt, the former head of the Army, raised fears over the funding of the 80 Joint Strike Fighter aircraft due to be ordered to fly from the carriers.

He told BBC News: "The big but is what's going to fly off them - because the Joint Strike Fighter programme is about £10bn, and that's what really frightens us."

Deputy First Minister Nicola Sturgeon is due to meet members of the opposition parties in Edinburgh on Monday to discuss a joint submission to the UK Strategic Defence and Security Review, to protect defence jobs and skills in Scotland.

Ms Sturgeon said: "These figures just expose the madness of considering the cancellation of the contracts for the two aircraft carriers."

First Minister Alex Salmond had written to Labour, the Liberal Democrats and the Conservatives on Friday inviting them to a meeting to make a joint submission.

HMS Queen Elizabeth and HMS Prince of Wales are due to launch in 2016 and 2018 respectively.