The Ministry of Defence has not had sight of the 2026 edition of the United States Government Accountability Office’s annual report on F-35 production and modernisation, a document the Pentagon has blocked from publication for the first time in more than two decades, according to a written answer published on Friday.
Luke Pollard, Minister of State for Defence Readiness and Industry, was responding to Ben Obese-Jecty, the Conservative MP for Huntingdon, who had asked whether the department had been given access to it. Mr Pollard said: “The Department has not had sight of the 2026 edition of the US Government Accountability Office report entitled F-35 Joint Strike Fighter: Update on Production and Modernization Efforts.”
The report exists and has been completed, but a GAO spokesperson told The Hill in July that it had been reviewed by the U.S. Department of War and marked as containing “Controlled Unclassified Information with no current plan to be released to the public”. The Pentagon declined to comment.
Congress mandated the annual review in statute, and the GAO has reviewed the programme every year for more than two decades, delivering a public verdict each time on cost, schedule, production and readiness. This is the first occasion on which the entire report has been kept from publication.
Controlled Unclassified Information is a handling designation, not a security classification, of course. Material marked that way is not secret in the ordinary sense, but its distribution is restricted, and in this case the restriction extends to a document whose public title has been published while its contents have not.
The 2025 report, the most recent to reach the public, gives a sense of what the withheld edition would have covered. It found that Lockheed Martin delivered 110 aircraft in 2024 and that every one of them was late, by an average of 238 days. Technology Refresh 3, the $1.9 billion suite of hardware and software upgrades on which the Block 4 modernisation depends, was running around three years behind schedule.
On Block 4, the GAO reported that the Department of War was redefining the subprogramme and expected it to comprise fewer capabilities than the original plan, deferring development of some to a future effort. The programme had told the GAO in 2018 that it planned to deliver 66 Block 4 capabilities by 2026, and by May 2024 the content had been revised and the completion date extended to 2029. Reporting on the same document put the cost growth at more than $6 billion above original estimates.
The same report carried a Department of War estimate putting the cost of Block 4, engine and power thermal management modernisation, and maintaining and operating the 2,470 planned aircraft across a 77-year life cycle, at more than $2 trillion. The GAO has separately reported that power and cooling shortfalls force the engine to work harder than its contractors intended, reducing its life expectancy, with programme officials estimating that the resulting wear has added $38 billion to the life cycle cost estimate.
What it means for Britain
Britain has been an F-35 partner since the earliest stages, at Level 1 alongside the United States, with British industry holding roughly 15 per cent of the workshare on every aircraft built, on paper at least. BAE Systems manufactures the rear fuselage at Samlesbury, Rolls-Royce produces the lift system for the short take-off and vertical landing variant, and Martin-Baker supplies the ejection seat.
Mr Pollard confirmed on the same day that discussions with the F-35 Joint Program Office are ongoing on procurement profiles and the delivery schedule for Britain’s next batch of aircraft, with delivery anticipated from the early 2030s. The Strategic Defence Review confirmed an intention to buy a further 27 aircraft, of which 12 are to be the F-35A conventional take-off variant to support Britain joining NATO’s dual capable aircraft nuclear mission.
A partner nation committing to further purchases while unable to see the most recent independent audit of the programme’s production performance is an unusual position.
We may not hav blocked it, but why have the Americans? All so good they don’t want to publish?