On a Thursday lunchtime in June, a Labour source sent a video of a single domino toppling over, then another, then hundreds – a metaphor for what they feared would follow the shock resignation of Defence Secretary John Healey. For the prime minister, Sir Keir Starmer, the dominoes are now wobbling dangerously.
The resignation of a defence secretary is always serious, but John Healey was no ordinary minister. He was seen as one of the most loyal figures in Labour politics, and his exit – over the government's refusal to increase defence spending – has blown a hole in Starmer's remaining protections. Healey's resignation letter explicitly said Number 11 (the Treasury) was "unwilling" to find the money for defence, while Number 10 (the Prime Minister's office) was "unable" to make it happen – a direct attack on Starmer's authority.
“Explains John Healey's resignation and the UK defence spending crisis”
The row centres on how much the UK should spend on its armed forces. At a time of war in Ukraine and conflict in the Middle East – including a recent war with Iran – Healey argued for a bigger budget. Sources say Downing Street was still debating on the night before the resignation whether to announce an extra £10bn, £13.5bn or £15bn for defence. One source told the BBC that "the deal was so bad they didn't know how to present it". Separately, Sky News reported that the UK's military chief had written to the prime minister expressing concern that an offer of around £13bn was not enough.
This is not just a budget squabble. It comes after months of speculation about Starmer's leadership, with dozens of Labour MPs reportedly saying he should quit and at least two potential leadership contenders waiting in the wings. Healey himself had been mentioned as a possible successor – a profile in the New Statesman, published before his resignation, noted that the 66-year-old defence secretary was "increasingly talked of inside Westminster as a possible contender for the Labour leadership".
For UK readers, the stakes are high. Defence spending is not an abstract figure: it funds the military that protects British interests abroad and at home. The resignation also raises questions about whether the government can function effectively under a leader who, according to one former cabinet minister, "has never got control of the Treasury, even though he's meant to be in charge". Starmer's allies had previously argued that his handling of security and foreign allies made him indispensable – but with Healey gone, that defence has collapsed.
Q: Why did John Healey resign as defence secretary? He resigned because he believed the government's defence budget settlement was too low, arguing it would put the country at risk. He said the Treasury was unwilling to find the money and Number 10 was unable to force the issue.
Q: What is the UK defence spending target being argued over? The UK currently spends around 2% of GDP on defence, but there are demands to increase this to 3%. Healey wanted a firm date to hit that target, but the Treasury offered only around £13bn more in the short term, which he judged insufficient.
Q: Could Keir Starmer face a leadership challenge now? Yes, the resignation has emboldened critics. Dozens of Labour MPs have already called for him to quit, and at least two leadership contenders are thought to be preparing bids. Healey's departure has removed a key loyalist and undermined Starmer's argument that he is essential on security.
What happens next is uncertain. The prime minister must now find a new defence secretary and try to calm the unrest in his party. But with the military chief already writing to him in protest, and the public row exposing deep splits at the top of government, the dominoes are still falling.