MoD still unclear on cost of RAF nuclear jet plan, MPs say

Ministers still do not know when RAF jets will be able to carry nuclear weapons or how much the project will cost, the Commons spending watchdog has found.

Sir Keir Starmer announced at the Nato summit in June that the UK would purchase 12 F-35A jets which could join the alliance’s airborne nuclear mission.

But, in a report published on Friday, the influential Commons Public Accounts Committee (PAC) said the Ministry of Defence had still not set out how much it would cost to operate the new jets.

The committee said the project was still “at an early stage”, with the Ministry of Defence (MoD) “starting to understand” the requirements of being certified for the Nato nuclear mission.

The MoD told the committee that the F-35As were “20% to 25% cheaper” than the F-35Bs currently operated by the RAF and Royal Navy “and slightly cheaper to support”.

But with the additional training and personnel required to join the nuclear mission, the committee said it was a “reasonable assumption that this may end up proving more expensive”.

The MPs added that the MoD was also yet to set out how long it would take to make the necessary arrangements for equipping the jets with nuclear weapons.

The F-35 is the most advanced fighter jet the UK has ever possessed, and the MoD expects the overall programme to cost £57 billion over its 56-year lifespan.

That figure is already triple the original estimate, but the committee said it did not include the costs of personnel, infrastructure and fuel, with the National Audit Office (NAO) suggesting an overall cost of £71 billion.

In July, the NAO issued a wide-ranging criticism of the F-35 programme, saying its return on investment had been “disappointing” and its capability remained below the MoD’s expectations.

The watchdog also criticised severe personnel shortages and “short-term affordability decisions” that hindered delivery of the aircraft and its full capabilities.

On Friday, the PAC reiterated many of these findings, accusing the MoD of “a pattern of short-term decision-making” that had led to increased costs.

The committee cited delays to investment in a facility to test the jet’s stealth capability, which saved £82 million in 2024-25 but added an extra £16 million to the overall cost; and delayed investment in infrastructure at 809 Naval Air Squadron until 2029, which both reduced capability and added almost £100 million in extra costs.

MPs also found the MoD had miscalculated the number of engineers needed per plane as it had failed to take into account staff taking leave or performing other tasks.

And they questioned the department’s intention to declare the F-35 to be at full operating capability by the end of the year, despite still not having a missile to attack ground targets from a safe distance.

Committee chairman Sir Geoffrey Clifton-Brown said: “Making short-term cost decisions is famously inadvisable if you’re a homeowner with a leaky roof, let alone if one is running a complex fighter jet programme – and yet such decisions have been rife in the management of the F-35.”

He added that the MoD had been “worryingly slow” to learn “basic lessons” from the project, and described its appraisal of the F-35’s overall cost as “unrealistic”.

Sir Geoffrey said: “The F-35 is the best fighter jet this nation has ever possessed. If it is to be wielded in the manner in which it deserves, the MoD must root out the short-termism, complacency and miscalculation in the programme identified in our report.”

An MoD spokesperson said: “This report rightly recognises the world-class capabilities of the F-35 fighter jet, which remains within the approved budget, supports 20,000 jobs across the UK and creates £22 billion of work for UK companies, backing defence as an engine for growth.

“Many of the decisions referenced in the report were taken under the previous government, and we have set out plans to tackle historic issues with procurement, infrastructure, recruitment and skills through the Strategic Defence Review.

“Our plans will ensure the programme delivers on budget, and for our Armed Forces, including having two full squadrons of F-35 fighter jets ready for deployment by the end of this year.”