Select Committee · Public Accounts Committee

The UK’s F-35 stealth fighter capability

Status: Open Opened: 10 Jul 2025 7 recommendations 23 conclusions 1 report

The F-35 is a fifth-generation stealth fighter aircraft, which is able to enter contested environments undetected. As part of a US-led programme, the Ministry of Defence (MoD) purchased and is using the F-35b variant, which can operate from land and aircraft carriers. The UK publicly committed to purchasing 138 F-35 aircraft from the global F-35 …

Clear

Reports

1 report
Title HC No. Published Items Response
51st Report - The UK’s F-35 stealth fighter capability HC 1232 31 Oct 2025 30 Responded

Recommendations & Conclusions

6 items
4 Conclusion 51st Report - The UK’s F-35 stealth fig… Acknowledged

Prioritise investment to complete RAF Marham accommodation improvements much earlier than 2034 timescale.

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, with at least 1,500 people working there on the F-35, …

Government response. 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
5 Conclusion 51st Report - The UK’s F-35 stealth fig… Acknowledged

Set out long-term impact of short-term savings and complete F-35 whole-life cost forecast.

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 …

Government response. 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
1 Conclusion 51st Report - The UK’s F-35 stealth fig… Acknowledged

Committee took evidence on Department's oversight and management of UK's F-35 programme.

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. 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
10 Conclusion 51st Report - The UK’s F-35 stealth fig… Acknowledged

F-35 availability and training significantly impacted by 2025 Carrier Strike Group deployment

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 Office’s report noted that the impact of the deployment on …

Government response. 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
14 Conclusion 51st Report - The UK’s F-35 stealth fig… Acknowledged

F-35 aircraft availability compromised by persistent personnel shortages and global support solution reset

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 Global Support Solution, which supplies spare parts, is being reset …

Government response. 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 …
HM Treasury
26 Conclusion 51st Report - The UK’s F-35 stealth fig… Acknowledged

Official F-35 whole-life cost figures significantly underestimate true programme expenditure, excluding key costs

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 of the National Audit Office report in 2025 this figure …

Government response. 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 …
HM Treasury

Oral evidence sessions

1 session
Date Witnesses
8 Sep 2025 Air Chief Marshal Sir Richard Knighton KCB · Ministry of Defence, Air Commodore Nick Lowe · Ministry of Defence, David Williams · Daily Mail, Dominic Wilson · Ministry of Defence View ↗

Correspondence

4 letters
DateDirectionTitle
14 May 2026 To cttee Letter from the Permanent Secretary at the Ministry of Defence relating to The …
20 Apr 2026 To cttee Letter from the Permanent Secretary of the Ministry of Defence to the Chair of …
26 Mar 2026 From cttee Letter to the Permanent Secretary at the Ministry of Defence relating to Treasu…
16 Oct 2025 To cttee Letter from the Permanent Secretary of the Ministry of Defence relating to the …