Select committee: Public Accounts Committee
Recommendation 11
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 ↗
Recommendation (the committee's words)
Although the F-35 is significantly superior to any previous UK aircraft, the Department has yet to achieve the capability or availability that it wants.19 Most significant is the lack of the standoff weapon.20 This will limit the UK’s ability to conduct certain missions in contested environments.21 The Department also told us that it had delayed building its sovereign Air Signature Assessment Facility (ASAF) to measure the stealth 12 Q 83 13 Q 81 14 Qq 88, 109 15 Q 104 16 Q 85 17 C&AG’s Report, para 1.21 18 Q 87 19 Qq 85, 104 20 Q 88 21 C&AG’s Report, para 1.11 8 characteristics of UK F-35 aircraft.22 Furthermore, aircraft availability is poor. The UK F-35 fleet achieved approximately one-third of the MoD target for the time it was able to fly all its required missions in 2024, and achieved only two-fifths of the level of availability of the global F-35B fleet between October 2024 and January 2025.23 The Department acknowledged that it was not getting the F-35 availability it wanted.24
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.