Britain withdrawing from developing next-generation fighter jets would be the equivalent of scrapping the Spitfire programme in the 1930s, according to the shadow defence secretary.

Conservative frontbencher James Cartlidge questioned the new Labour Government’s commitment to the Global Combat Air Programme (GCAP) amid concerns its immediate funding is in doubt.

The GCAP brings together the UK, Italy and Japan to work on delivering next generation combat aircraft in 2035.

The planes will be known as Tempest in the UK and serve as a successor to the RAF Typhoon.

On Wednesday, MPs approved legislation which Foreign Office minister Catherine West said would provide the legal framework for the programme, adding it did not include specific funding recommendations.

The new Government is conducting a strategic defence review although Mr Cartlidge raised concerns about the impact it could have on Tempest development.

Mr Cartlidge told the Commons: “Alongside this SI (statutory instrument), we need the Government to wholeheartedly back the GCAP programme, ensuring that it has the funding necessary to deliver our sixth generation fighter capability.”

Turning to the Treasury, Mr Cartlidge added: “I suspect the overall question as to whether the Government is committed to GCAP or not is a red herring.

“What really matters is whether they’re committed to funding it this year, with important spending decisions to be made right now.

“They’ll be in the inbox of the Secretary of State, funding decisions on GCAP, and we want to see them continuing that funding in the years beyond and we want to know whether they’re using this review as a chance to shift spending decisions to the right.”

Mr Cartlidge said it was “not unprecedented” for the Treasury to work in this way under previous governments, saying: “Offering illusory short-term savings but causing immediate and lasting pain to the most important conventional defence programme of our time.”

The shadow defence secretary highlighted the need to push on with the GCAP, adding: “Overall, this is my view, I happen to believe that withdrawing from GCAP now would amount to the equivalent of scrapping the Spitfire programme in the 1930s – it is that serious.”

Mr Cartlidge said the Tempest programme was previously estimated to support an average of 20,000 jobs every year, adding: “Scrapping GCAP would hit our economy hard.

“Even delaying or deferring GCAP expenditure will undermine our brilliant aerospace industry… and cast doubt over vast sums of private investment that’s waiting from which hundreds of UK SMEs would stand to benefit.”

Opening the debate, Ms West said the new aircraft under development would “sit at the heart of a wider system”, including the F-35 and “broader military capabilities”, and would “sustain the UK’s operational advantage”.

Intervening, Mr Cartlidge asked: “Can she confirm there will be no delay to the current planned spending this year on GCAP by the Ministry of Defence?”

Ms West replied: “This instrument today, to be clear to members new and old, is the legal framework which the programme will sit within.

“This hasn’t got specific funding recommendations attached to it because it’s the scaffolding, if you like it’s the nest within which all the work will happen.”

In response to Tory former defence minister Andrew Murrison accusing the new Government of “procrastination”, Ms West said: “There’s been no procrastination.

“Within the month of being elected we’ve got the legal framework to the House of Commons for a debate and I think that is expediting all the important organisational arrangements so that this programme can proceed at pace.”

Conservative former defence minister Mark Francois said the Government’s defence review has been interpreted by some “as a sword of Damocles now hanging over” the UK’s agreement with Japan and Italy.

Earlier at Prime Minister’s Questions, Conservative Party leader Rishi Sunak sought assurances that the Government would continue talks with Saudi Arabia about their possible involvement in the project.

Prime Minister Sir Keir Starmer replied: “This is a really important programme, significant progress has already been made and we want to build on that progress and I’ve had some initial discussions, not least in Farnborough, where I was just a few days ago.”