Select committee: Public Accounts Committee
Conclusion 22
51st Report - The UK’s F-35 stealth fighter capability
Published 31 Oct 2025
Addressed to HM Treasury
Public Accounts Committee The UK’s F-35 stealth fighter capability All items in this report Report on parliament.uk ↗ Inquiry on parliament.uk ↗
Conclusion (the committee's words)
The Department acknowledged that it has, on occasion, prioritised short-term affordability over value for money in the F-35 programme, to keep within its overall departmental budget.46 Notably, in 2021 the Department took the decision to delay investment in the Air Signature Assessment Facility (ASAF). Although this decision saved £82 million in the short-term out to 2024–25, it will have cost the Department £16 million more than that by 2031–32 because of inflation resulting from choosing to build later. The Department viewed this as a “conventional consequence” of managing an annual departmental budget covering many programmes.47
From: Public Accounts Committee, 51st Report - The UK’s F-35 stealth fighter capability (HC 1232), 31 October 2025
Government response
Latest Treasury Minutes progress report to the Committee of Public Accounts on the Fifty-first Report of Session 2024-26
The government responded to the whole report on 4 June 2026 (deadline 31 December 2025).
Treasury minutes: Government response to the Committee of Public Accounts on the Fifty-first report from Session 2024-26
Published 19 January 2026.
Summary written by Accountability Index from the government's response. It is not the government's own words.The government agrees with most of the Committee's recommendations on the F-35, disagreeing on a F-35-specific workforce plan and on updating the Committee on Dual Capable Aircraft costs.
- On Full Operating Capability, the government agrees that criteria should take account of capability gaps and sustainment, with a target implementation date of November 2026.
- It agrees to write to the Committee by 30 April 2026 on increasing F-35 availability, saying the longer timeline is needed to draw on lessons from Carrier Strike Group 25.
- It disagrees with producing an F-35-specific recruitment and retention plan and will instead address the issue through the "ongoing RAF People Campaign".
- On RAF Marham accommodation, it will write by 31 May 2026 to advise "whether" the current timescale can be brought forward, after infrastructure requirements are reassessed following the Defence Investment Plan.