In a move that sent shockwaves through Westminster, John Healey resigned as defence secretary on 11 June 2026, accusing the prime minister and chancellor of putting the country's security at risk. His resignation – the sixth ministerial departure in a month – came after months of wrangling over the Defence Investment Plan (Dip), the blueprint for equipping Britain for future conflicts. The row has exposed a bitter divide between the Treasury and the Ministry of Defence over how much the UK should spend on its armed forces at a time of rising global threats.
The Defence Investment Plan is the government's long-term strategy for funding major military projects, including the £41bn Dreadnought submarine programme that replaces the Trident nuclear deterrent, investment in drones for a future Ukraine-style war, and the Aukus nuclear-powered submarine partnership with Australia and the US. It is also central to the UK's commitment to Nato: in 2025, Starmer agreed to lift defence spending from 2.6% of GDP to 3.5% by 2035 – nearly £30bn in real terms. The plan was due to be published on 11 June, but Healey refused to release it after being told the Treasury would only provide an extra £2bn (0.08% of GDP) by 2030. In his resignation letter, he wrote that Starmer had been “unable” and the chancellor, Rachel Reeves, “unwilling” to commit the resources needed, adding: “Your Dip financial settlement falls well short of what is required.” Within hours, armed forces minister Al Carns also quit, saying the plan was “not built for the threat we face”. Dan Jarvis, the security minister, was named as Healey's successor.
“Why the UK defence spending row led to John Healey's resignation and what it means for national security.”
The roots of this crisis stretch back years. UK defence spending has been a persistent political faultline, with successive governments struggling to balance Nato commitments against domestic spending pressures. Under the Conservatives, defence budgets were cut in real terms, and Labour came to power promising to “put security first” – but the Treasury’s fiscal rules have constrained spending. In private, Healey had been locked in a months-long row with Reeves, culminating in a reported “stand-up row” the day before his resignation. A government minister told the i newspaper that the Treasury was a “disgrace”, while another source said it was a “danger” to national security.
For UK readers, this matters because defence spending directly affects national security. The UK is a leading Nato member, co-leading peacekeeping plans for Ukraine and a multinational force for the Strait of Hormuz. It has pledged to stand with allies against threats from Russia, Iran and elsewhere. But if the government cannot agree on funding, those promises risk being hollow. The resignation also leaves Starmer weakened just before a G7 meeting in France and a Nato summit in Ankara, where Donald Trump – the US president – is expected to attend. Healey’s departure undermines Starmer’s reputation as a safe pair of hands and raises questions about the UK’s reliability as a defence partner. Q: What is the Defence Investment Plan? The Defence Investment Plan (Dip) is a long-term government strategy to fund major military projects, such as the Dreadnought submarine programme and drone investment. It is designed to ensure the UK meets its Nato spending commitments and can equip its forces for future conflicts. Q: Why did John Healey resign? Healey resigned because the Treasury offered only an extra £2bn by 2030 for defence, far less than he believed was needed. He accused the prime minister and chancellor of putting the country’s security at risk and said the Dip settlement “falls well short of what is required”. Q: What happens next? Healey’s successor, Dan Jarvis, must now rebuild the MoD’s relationship with the Treasury and finalise the Dip. Starmer faces a Nato summit in Ankara and G7 meetings with allies, where he will have to explain why his own defence secretary resigned. Some Labour MPs believe the crisis makes a leadership challenge more likely. The immediate future is uncertain. Starmer has insisted the Dip will be funded properly, but Healey’s resignation has shredded his political authority. With a Nato summit weeks away and Donald Trump demanding allies spend more, the UK must quickly restore credibility. The new defence secretary, Dan Jarvis, will have to negotiate a viable plan while managing the fallout. The crisis also fuels speculation about a leadership contest, with Andy Burnham tipped as a potential successor after an upcoming byelection. What is clear is that the battle over defence spending – and the question of how much Britain is willing to pay for its security – is far from over.