Labour MP and Commons Defence Committee chair Tan Dhesi has publicly challenged his own Government to commit to spending 3% of GDP on defence by 2030, warning that decisions over military funding should not be deferred until next year.
Dhesi said renewed tensions surrounding Argentina's claim to the Falkland Islands had made the need for greater defence investment more urgent.
His intervention places further pressure on Prime Minister Andy Burnham following confusion over the Government's timetable for reaching the 3% threshold.
Dhesi tells Government not to delay
Dhesi said the Prime Minister and Chancellor should not wait until next year before making the necessary decisions on defence funding.
Speaking to the Guardian, he said: “It's important the prime minister and the chancellor don't defer those decisions to next year.”
The Defence Committee chair linked his intervention to the wider deterioration in the international security environment, including Russia and the renewed sovereignty dispute between Britain and Argentina over the Falkland Islands.
Falklands dispute adds to pressure
Dhesi referred to recent statements by Argentine President Javier Milei as he argued that Britain must be capable of defending the Falkland Islanders' right to self-determination.
He said: “We owe it to the Falklands – they say it's their right to self-determination. It's important that we also defend them from this threat.”
Argentina continues to claim sovereignty over the islands, while the UK Government maintains that their political future is for the islanders themselves to determine.
The latest intervention follows an escalation in the dispute over offshore oil development around the islands, with Argentina announcing sanctions measures connected to the Sea Lion project.
Confusion over Burnham's 2030 position
The row comes after Burnham appeared during Prime Minister's Questions to indicate that the Government was committed to reaching 3% of GDP on defence by 2030.
Downing Street subsequently clarified that the Prime Minister had not made a new commitment to that date.
The Government's existing Defence Investment Plan puts spending on a trajectory towards 3% in the next Parliament rather than establishing 2030 as a firm deadline.
That distinction has become increasingly politically significant as MPs press ministers for greater certainty over the resources available to the Armed Forces.
Defence Committee has repeatedly demanded clarity
Dhesi's intervention is consistent with warnings already issued by the cross-party Defence Committee.
Following publication of the Defence Investment Plan in June, Dhesi welcomed additional investment but criticised the absence of a clear timetable for reaching 3% of GDP.
He warned at the time that the lack of a defined pathway risked leaving Parliament and the defence industry without sufficient visibility over future capability, funding and delivery.
Dhesi has previously argued in Parliament that Britain should reach 3% during the current Parliament and should not “kick the can down the road”.
Government faces difficult spending choices
Moving more quickly to 3% would require billions of pounds of additional annual defence expenditure and force the Government to decide how the increase would be funded.
The Conservatives have separately pledged to reach 3% by 2030 and say they would finance an additional £10 billion a year for defence through substantial reductions in welfare spending.
Labour has not adopted that funding model, leaving Burnham and the Chancellor facing pressure to explain how a faster increase in military expenditure could be reconciled with the Government's wider spending and fiscal commitments.
Pressure follows concerns over military readiness
The dispute over the 3% target comes amid broader scrutiny of the resources available to Britain's Armed Forces.
The Army has recently confirmed that it is prioritising training activity most directly connected to readiness, deployability and operational effectiveness, following reports that some exercises were being curtailed.
Meanwhile, the Ministry of Defence has continued to highlight the growing threats facing Britain and its allies, including through increased activity in NATO's High North.
Dhesi's intervention therefore turns an existing argument over the long-term defence budget into a more immediate political challenge for the new Prime Minister: whether to attach a firm 2030 deadline to the 3% commitment or continue to leave the precise timetable to future spending decisions.