A cross-party committee of MPs has warned that delays to the UK government’s long-awaited Defence Investment Plan have harmed the country’s credibility with allies and created uncertainty across the defense sector.
The criticism comes as ministers continue to finalize the plan, which is expected to outline how military capabilities, equipment, and infrastructure will be funded over the coming decade.
The Defence Investment Plan (DIP) was originally expected in the autumn following the publication of the Strategic Defence Review in June 2025. The document has yet to be released, though Prime Minister Keir Starmer has said it will be published before the NATO summit scheduled for next month.
According to a report from the Public Accounts Committee (PAC), the delay has weakened confidence among allies, affected defense suppliers, and complicated efforts to modernize the armed forces during a period of heightened international tensions.
MPs Warn of Damage to Military Planning and Industry Confidence
The PAC said the absence of the investment plan has left the Ministry of Defence (MoD) without a clear funding framework to support the ambitions set out in the Strategic Defence Review.
According to the committee, delays in procurement risk increasing costs as defense contractors raise prices amid global instability. The report also stated that postponing investment decisions could hinder the armed forces’ ability to acquire equipment needed for modern warfare and strengthen deterrence capabilities.
Sir Geoffrey Clifton-Brown, chair of the PAC, delivered some of the strongest criticism. He said the country had effectively gone years without a credible plan for military capability and argued that explanations centered on taking additional time to refine the details were inadequate.
The committee also highlighted the impact on defense companies, particularly small and medium-sized firms that had been awaiting greater certainty over future contracts and investment priorities. According to Sky News, some businesses had expected to expand production capacity in preparation for potential future conflicts but were left waiting for decisions linked to the delayed plan.
An MoD spokesperson defended the government’s approach, saying officials were working to finalize the DIP and describing it as a means of addressing what it called an outdated and underfunded program inherited by the current administration.
Concerns Extend to Ajax Vehicles and Nuclear Spending Oversight
Beyond the delayed investment plan, the PAC report examined several ongoing defence programs and spending issues.
One area of concern was the Ajax armored vehicle program. According to the PAC, 33 soldiers had been affected by noise and vibration-related issues associated with the vehicles, with five individuals still under medical review as of March. The committee questioned whether maintenance checks required after each use would be practical during extended combat operations.
The report also noted that an upgraded “Ajax 2” package is being developed, though the committee said it had not been provided with information about the likely costs. The PAC stated that it would monitor whether those efforts succeed.
Nuclear spending was another focus of scrutiny. According to the committee, the MoD spent 18% of its defense budget, equivalent to £10.9 billion, on the UK’s nuclear deterrent, with that share expected to rise in the coming years. MPs said they had not received sufficient transparency regarding the costs and performance of the nuclear enterprise.
The PAC also raised concerns over accounting records linked to more than £6 billion in assets. The committee described this as an unacceptable failure and called for improved financial reporting and greater parliamentary oversight.
The report makes six recommendations for the MoD, including providing updates on the investment plan, improving transparency on nuclear spending, addressing recruitment challenges, and explaining when Ajax vehicles are expected to become fully fit for purpose.
