51st Report - The UK’s F-35 stealth fighter capability
Select Committee
Public Accounts Committee
HC 1232
31 October 2025
Government response
Treasury minutes: Government response to the Committee of Public Accounts on the Fifty-first report from Session 2024-26 · published 19 Jan 2026
Recommendations & Conclusions
6 results
4
Conclusion
Acknowledged
Prioritise investment to complete RAF Marham accommodation improvements much earlier than 2034 timescale.
Conclusion
Accommodation at RAF Marham is substandard, exacerbating issues with recruitment and retention. Despite the urgent need to address this, upgrades will not be completed under current plans until 2034. RAF Marham has been the main F-35 operating base since 2013, …
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Government Response Summary
The government agreed to prioritize improvements to RAF Marham accommodation and committed to reassessing the current timescale against departmental priorities, writing to the Committee by May 2026 to advise if the completion date can be brought forward.
HM Treasury
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5
Conclusion
Acknowledged
Set out long-term impact of short-term savings and complete F-35 whole-life cost forecast.
Conclusion
The Department has taken a narrow and short-term approach to management and costs and has failed to realistically appraise the programme’s whole-life cost. The Department acknowledges that it reduced the pace of aircraft deliveries to make short-term financial savings at …
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Government Response Summary
The government agreed to include all non-equipment costs in whole-life cost forecasts, stating it already develops such models but accepts there is an opportunity to go further and will strengthen its approach as part of Defence Reform.
HM Treasury
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1
Conclusion
Acknowledged
Committee took evidence on Department's oversight and management of UK's F-35 programme.
Conclusion
On the basis of a report by the Comptroller and Auditor General, we took evidence from the Ministry of Defence (the Department) on its oversight and management of the UK’s F-35 fighter programme.1
Government Response Summary
The government agreed with the committee's implicit recommendation on oversight, stating it will continue to strengthen its approach to defining and approving capability entry-into-service criteria and declaring service entry for new capabilities as part of Defence Reform.
HM Treasury
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10
Conclusion
Acknowledged
F-35 availability and training significantly impacted by 2025 Carrier Strike Group deployment
Conclusion
The Department also told us that the 2025 CSG deployment, required for FOC declaration, had impacted availability before the deployment and would impact availability for some weeks after the deployment, because of the need for additional maintenance.16 The National Audit …
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Government Response Summary
The department acknowledges the factors affecting aircraft availability and is increasing the number of aircraft engineers, supporting the US-led F-35 Joint Programme Office, and planning further investments in F-35 technical infrastructure.
HM Treasury
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14
Conclusion
Acknowledged
F-35 aircraft availability compromised by persistent personnel shortages and global support solution reset
Conclusion
The Department also set out the reasons for poor availability of aircraft. It accepted that shortages of personnel, particularly engineers, impacted aircraft availability, and would continue to do so until they were resolved.30 Furthermore, the Department told us that the …
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Government Response Summary
The department is increasing the number of aircraft engineers to align with Force readiness requirements, and is supporting the US-led F-35 Joint Programme Office in efforts to reset the Global Support Solution to improve performance and increase spares availability. The department is planning further investments in F-35 technical infrastructure at RAF Marham and enhancements to supporting enablers through improvement initiatives.
HM Treasury
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26
Conclusion
Acknowledged
Official F-35 whole-life cost figures significantly underestimate true programme expenditure, excluding key costs
Conclusion
In 2013 the Department set out a whole-life cost for the F-35 programme of £18.4 billion, although this only covered the first 48 aircraft out of the 138 that the UK has announced it intends to buy. Before the publication …
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Government Response Summary
The department will continue to strengthen its approach to whole life cost modelling as part of the work that is being taken forward under Defence Reform. The department already develops whole life cost models that extend beyond equipment costs, for example covering personnel and infrastructure costs too, but accepts that there is an opportunity to go further in developing and presenting a fuller and more complete view of through-life cost.
HM Treasury
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