The United Kingdom's Defence Secretary, John Healey, has resigned. The news broke as a major political development, with his resignation letter made public shortly afterwards.
In the letter, Mr Healey delivered a stinging criticism of the government's defence investment plan, which had been expected to be unveiled in the coming days. The plan covers multiple years of spending on areas such as defence infrastructure.
At the heart of his resignation is the argument that the plans being proposed by Prime Minister Sir Keir Starmer are inadequate. After months of internal wrangling over the proposal, he concluded that he could not support the version that had been put forward.
According to the letter, the plan in the form proposed by Sir Keir Starmer would increase the risk to British Armed Forces personnel when they are on military operations. In effect, the outgoing Defence Secretary is warning that the Prime Minister's proposal would put the Armed Forces at greater risk.
That is about as serious a charge as a Defence Secretary can make against a Prime Minister. It turns what had been a dispute over spending and planning into a direct warning about the safety of military personnel.
The defence investment plan itself has had a long and troubled path. It had been haggled over within government for months, amid tensions over which departments' budgets would have to be reduced in order to fund it.
The plan had been due to be delivered before the upcoming NATO summit. The resignation lands as a grave political crisis for the Prime Minister, coming at a moment when he can ill afford one.
The plan had been released last autumn, but its publication had been delayed. According to reports, the Ministry of Defence had asked for an extra 28 billion pounds over the next four years, and Mr Healey said the settlement he was given in full on Monday afternoon fell well short of what was required.
Even as he stepped down, Mr Healey is understood to have asked the government's other defence ministers to stay in post in order to minimise disruption. His departure is also significant in a wider sense, as he is the sixth minister to resign from Sir Keir Starmer's government in the space of a month.
The government, in its first response, pushed back on the criticism. A source said the country is safer because of the decisions Sir Keir Starmer has made, and that the government would continue to act in the national interest. The source argued that this Labour government was delivering the largest sustained boost to defence spending since the Cold War, that the international aid budget had been cut to make a record investment in the armed forces, and that the Prime Minister was now imposing cuts on other departments to fund billions more. The Defence Investment Plan, the source said, would deliver the capability the armed forces need.