John Healey quitting defence puts a time bomb under No 10. He is a loyalist: this is no ordinary departure

He served through the eras of Blair, Brown, Miliband and Corbyn in a party that knows and respects him. It will matter that even his patience has run out

J ohn Healey is not a rash man. Slow to anger, calm in a crisis, loyal and yet beneath it all, formidably determined. He stuck at it through the Jeremy Corbyn years, much as he privately despaired of where the party was heading, keeping his thoughts to himself because all he wanted was for Labour to win again. When it did, under Keir Starmer , he became the understated anchor to a frequently gale-tossed ship of government; the solid citizen everybody liked and nobody distrusted, a natural choice for caretaker leader had Starmer ever fallen under a bus.

For a defence secretary to resign weeks before a critical Nato summit, in the middle of conflict in the Gulf and on the eve of a domestic byelection which will determine his party’s future, is extraordinary in itself. But it’s that bayonet of a resignation letter – painting the prime minister as weak and impotent, incapable even of finding the money to keep the nation safe – that now threatens to finish off an already badly wounded premiership.

Despite accepting the case for more defence spending, Healey wrote to Starmer , “you have been unable, and the Treasury has been unwilling” to find the money to keep the nation safe. That “unable” is the key, reflecting what is said freely behind closed doors: that a prime minister who always hated settling cabinet disputes even at his peak is now a lame duck, drained of all authority over ministers who don’t expect him to survive the summer. The inference is that if the chancellor, Rachel Reeves – sceptical of the Ministry of Defence’s numbers, and hemmed in by her own tax promises – says no, then her nominal boss is too weak either to override her or to force cuts on any other cabinet ministers to get the money. So what, exactly, is the point of him?

In failing to find the cash, Healey added, Starmer and Reeves between them were forcing him to take decisions that “increase the risk to personnel on operations” – words liable to be taken particularly seriously by military families given the loss of four serving personnel in training accidents this month. The last straw seems to have been a settlement that would see Britain spending barely any more in 2030, the point at which Nato member countries calculate that Russia might have rearmed sufficiently to mount a significant attack, than it’s already budgeting for the coming year. But as with Jess Phillips’s resignation letter , lambasting the prime minister’s failure to legislate on measures she believed could save children from abuse, what’s striking is the sense of someone coming to the very end of their tether.

Healey has been at this game long enough to know how his words will reverberate, not just around Westminster but in Washington and Moscow, Beijing and Kyiv. But they’re unlikely to come as much of a surprise in any of those capitals, given that this government has been visibly struggling for over a year now with the conclusions of its own defence spending review. Venting his frustration out loud may, perhaps, be seen as the last best hope of forcing something to change.

Ominously for Starmer, ministers did not exactly rush to close ranks. The former Royal Marine turned junior defence minister Al Carns tweeted defiantly that his boss had given the country “serious service at a serious time” and that “there are issues facing this department that do not lend themselves to easy answers”. The Plymouth Moor View MP, Fred Thomas, another ex-Marine and member of the defence select committee, called openly ( not for the first time ) on Starmer to resign . Yet if this is a humiliating moment for the prime minister, it’s not exactly a vote of confidence for the heir apparent either.

Why didn’t Healey wait a week, until after Andy Burnham had had his shot at returning to parliament as MP for Makerfield? In part, perhaps, because Britain’s allies can’t wait. Nato members are preparing for a critical July summit to discuss the two existential security threats they face – one from an increasingly aggressive Russia, the other from Donald Trump’s desire to pull US troops and assets out of Europe. They need to know exactly where Britain is capable of plugging the gaps, and how fast it can move towards its target of spending at least 3.5% of GDP on defence (plus another 1.5% on resilience) by 2035.