Al Carns has delivered a withering assessment of the government’s defence plans after quitting as defence minister, accusing ministers of not spending enough money on the military and spending it on the wrong weapons.Carns quit the government on Thursday night, hours after the resignation of his boss, John Healey, after a protracted row over the defence investment plan (Dip).The former armed forces minister said on Friday he had quit because the Dip had not been well enough funded, but also because the government was planning to spend its money on outdated systems. He also hinted heavily that he would run for leader should a contest be triggered in the coming weeks.Carns told the BBC’s Today programme: “I didn’t think the funding settlement was correct for defence, and I didn’t agree with the defence investment plan, which I thought was looking at how to fight the last war rather than the next one.”He added: “Some of the old legacy capabilities that we have – in fact, that weren’t even ordered by us, were ordered by the Conservative party many, many years ago – some difficult, courageous decisions need to be made to get rid and replace them with some of the innovative technologies we’re seeing in Ukraine.”Asked by LBC’s Nick Ferrari whether he would consider standing as leader if “the ball comes out from the back of the scrum”, he said: “I’m good at rugby and football, but we’ll see what happens … I’m always up for playing.”Carns’ resignation on Thursday night compounded another difficult day in office for Keir Starmer, whose previously loyal defence secretary, Healey, resigned earlier in the day after weeks of fighting over funding.Ministers have been arguing for months about the long-delayed plan, for which the Ministry of Defence wanted £18bn over four years, but for which the Treasury was only willing to pay £13.5bn – of which £10bn was new money.Healey said in his resignation letter: “You have been unable and the Treasury has been unwilling to commit the resources that the nation needs to defend the country at this time of rising threats.”His broadside punctures a hole in the prime minister’s argument that he is best placed to lead the country at a time of geopolitical turmoil, as he prepares to face a possible challenge should Andy Burnham win the Makerfield byelection next week.Carns said on Friday that he respected the prime minister, but painted a picture of a leader that was unable to settle disputes within his own government. “I generally think Keir Starmer is a good man, he’s an honest man, and he’s an integral man,” he said.“But we are fighting amongst each other to get more money for the key unifying principle of the of any government, which is to protect this nation.”Peter Kyle, the business secretary, defended the prime minister, saying he needed to prioritise growth as well as giving the military more money.“If we did [the Dip] in a way that was irresponsible, then you’d end up impacting the growth of our economy, and it would be a zero-sum game,” he told Sky News, as he instsed the plan would be published before next month’s Nato summit.“It would be fool’s gold if we did so in an irresponsible way.”