Ministry of Defence still unclear on cost of RAF nuclear jet plan, MPs say
Ministers still do not know when RAF jets could carry nuclear weapons or how much the project will cost, the Commons spending watchdog has found.
In a report published on Friday, the influential Commons Public Accounts Committee (PAC) said the Ministry of Defense (MoD) had not yet determined how much it would cost to operate the new F-35A jets.
Sir Keir Starmer announced at the NATO summit in June that the UK would purchase 12 jets capable of participating in the alliance’s airborne nuclear mission.
The committee said the project was still in the “early stages” and that the Department of Defense was “beginning to understand” the requirements for certification for the NATO nuclear mission.
The Ministry of Defense told the committee that F-35As are “20 per cent to 25 per cent cheaper” than the F-35Bs currently operated by the RAF and Royal Navy, and are “slightly cheaper to support”.
But with the additional training and personnel required to participate in a nuclear mission, the committee said there was a “reasonable assumption that this could be more expensive.”
The MPs added that the Ministry of Defense had not yet determined how long it would take to make arrangements for the jets to be equipped with nuclear weapons.
The F-35 is the most advanced fighter jet the UK has ever had and the Ministry of Defense expects it to cost £57bn over the 56-year life of the overall programme.
This figure is already three times the original estimate, but the committee notes this does not include staff, infrastructure and fuel costs, while the National Audit Office (NAO) suggests the total cost is £71bn.
In July, the NAO issued a wide-ranging criticism of the F-35 program, saying its return on investment was “disappointing” and its capability fell short of the Defense Department’s expectations.
The watchdog also criticized serious personnel shortages and “short-term affordability decisions” that hindered delivery of the aircraft and its full capabilities.
On Friday, the PAC echoed many of those findings and accused the Department of Defense of a “pattern of short-term decision-making” that has led to rising costs.
The committee noted delays in investing in a facility to test the jet’s stealth capability; this saved £82 million in 2024-25 but added an extra £16 million to the total cost; and delayed infrastructure investment at 809 Naval Air Squadron until 2029, both reducing capacity and adding almost £100 million in extra costs.
Lawmakers also found that the Department of Defense miscalculated the number of engineers needed per aircraft because it did not account for personnel taking leave or performing other duties.
They also questioned the ministry’s intention to declare the F-35 to be fully operational by the end of the year, despite not yet having a missile that can attack ground targets from a safe distance.
Sir Geoffrey Clifton-Brown, chairman of the committee, said: “Making short-term cost decisions is certainly not advisable when you are a homeowner with a leaky roof, let alone running a complex fighter jet program – and yet such decisions were quite common in the management of the F-35.”
He added that the Department of Defense had been “alarmingly slow” to learn “key lessons” from the project and called his assessment of the F-35’s overall cost “unrealistic.”
Sir Geoffrey said: “The F-35 is the best fighter jet this country has ever had. If it is to be used as it deserves, the Ministry of Defense must eliminate the short-termism, complacency and miscalculation in the program outlined in our report.”
A Ministry of Defense spokesman said: “This report rightly recognizes the world-class capabilities of the F-35 fighter jet, staying within the approved budget, supporting 20,000 jobs across the UK and creating £22bn of jobs for UK companies, supporting defense as an engine of growth.
“Many of the decisions referred to in the report were taken under the previous government and we have drawn up plans to address historic problems around procurement, infrastructure, recruitment and skills through the Strategic Defense Review.
“Our plans will ensure the program is delivered 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.”
