Select committee: Public Accounts Committee
Conclusion 5
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 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 multiple points in the programme, notably in 2010. In 2021 the Department decided to pause building a sovereign facility for assuring that aircraft retained their stealth capabilities, which is required for its freedom of action policy. The Department similarly delayed providing 809 Naval Air Squadron’s infrastructure by 6 years, increasing costs by almost £100 million. It did so despite knowing it would cost more money in the long-term and create a gap in capability. The Department also failed for many years to significantly update its public whole-life cost, which hardly increased from its 2013 estimate of £18.425 billion covering the first 48 aircraft to the then out of service date of 2048. In response to the 2025 National Audit Office report the MoD published a whole-life cost of almost £57 billion for all 138 aircraft to the new out of service date of 2069. But this still does not include non-equipment costs such as personnel, fuel and infrastructure which are included in the NAO estimate of £71 billion. recommendation The Department should: a. set out in its upcoming Defence Investment Plan the expected long-term impact on costs and capability of any short-term savings measures, on both the F-35 and other major programmes, and b. build on its recent whole-life cost analysis by including all relevant non-equipment costs to give a more complete through-life cost forecast of the programme. 4
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.