Prime minister promises to fight any leadership challenge as he faces escalating row over military spending

Keir Starmer has admitted that he has to “turn things around” after the resignation of the defence secretary, John Healey, in an escalating row over military spending that has prompted recriminations across Whitehall and concern from the US.

Downing Street and the Treasury traded blows with allies of Healey on Friday. No 10 expressed dismay that the Ministry of Defence (MoD) had wanted £18bn to plug funding gaps in major projects, while those close to the former defence secretary accused Starmer of failing to acknowledge the deterioration in global security.