Delays in Defence Investment Plan Harm UK Credibility, MPs Warn
Delays in publishing the government's Defence Investment Plan (DIP) have undermined the United Kingdom's credibility with its allies, according to the Public Accounts Committee (PAC), which oversees public spending.
The DIP, initially scheduled for release in autumn, is now expected to be published ahead of a NATO summit early next month. The PAC highlighted that this postponement will increase the cost of procuring new equipment, thereby "hindering the government's attempt to modernise the Armed Forces."
A Ministry of Defence (MoD) spokesman stated that the DIP would "fix the outdated, overcommitted and underfunded programme we inherited," adding, "We are working hard to finalise it." The DIP will outline funding plans for new equipment and defence infrastructure over the next decade, following the Strategic Defence Review (SDR) published on 2 June 2025.
Defence Secretary John Healey informed the House of Commons on Monday that Prime Minister Sir Keir Starmer was "determined to publish" the plan.
Public Accounts Committee Criticises Lack of Credible Defence Plan
Sir Geoffrey Clifton-Brown MP, chair of the PAC, remarked that the nation has "now in fact gone years without a credible plan for UK military capability."
"Those responsible may argue there are good reasons for the DIP's continuing absence, but our report makes clear that excuses to the effect of 'taking the time to get the details right' simply do not cut it."
The PAC report attributed the DIP's delay to the MoD's indecision regarding the capabilities, infrastructure, and personnel required to transform the Armed Forces into a warfighting-ready force.
It further noted that defence contractors are increasing prices due to global instability, meaning procurement delays could lead to higher costs.
Moreover, postponing the DIP's release has resulted in an "inability to equip the UK's Armed Forces for the modern battlefield" and to provide a stronger deterrent, thereby undermining the MoD's credibility with both the UK's allies and the defence sector.
In response, the MoD spokesman emphasized that since the government took office in July 2024, it has signed over 1,400 major defence contracts and is delivering "a generational increase in defence spending... ensuring no return to the hollowed out armed forces of the past."
Concerns Over Ajax Armoured Vehicle and Defence Spending
The PAC report also raised specific concerns about current defence expenditures, including ongoing issues with the Ajax armoured vehicle.
In November 2025, the army paused use of the Ajax vehicles after soldiers experienced adverse effects from noise and vibration, with some vomiting after exiting the vehicles.
The report found that 33 soldiers were affected by these issues, with five still under medical review as of March.
The MoD now expects soldiers to perform maintenance checks every time they stop the vehicles, which the PAC described as "unreasonable" given the potential need to operate the vehicles for extended periods in combat.
It called on the MoD to explain how the current operating restrictions were realistic and appropriate.
The report stated,
"With an Ajax 2 package of upgrades now in development at an unknown cost, the PAC awaits to see, more in hope than expectation, whether these endeavours will succeed."
The Ajax vehicles currently in use are for trial purposes only. It is understood that the government is proceeding cautiously with the programme and recognizes the need to rebuild confidence in the vehicles before full deployment.
Transparency Issues in Nuclear Expenditure
The PAC also expressed concerns regarding the MoD's lack of transparency over its increasing nuclear expenditure.
The MoD allocated 18% (£10.9 billion) of its defence budget to the UK's nuclear deterrent, a figure expected to rise to as much as 25% in coming years.
The UK is constructing new Dreadnought-class submarines to carry Trident nuclear missiles, with an estimated cost of £31 billion, although recent tests of the US-made missiles have failed.
The PAC urged the MoD to clarify how and when it will provide Parliament with detailed cost and performance information about the nuclear programme.
The report also highlighted a "completely unacceptable failure to maintain accounting records to support £6bn+ of assets" in the MoD's accounts.
The MoD reportedly attributes the £6.1 billion discrepancy to accounting methods for funds paid over the past 15 years.
Recommendations and Future Outlook
The PAC report concludes with six recommendations for the MoD to address these issues.
