Keir Starmer was branded “lazy and incompetent” in a furious attack by Conservative leader Kemi Badenoch – who demanded he resign over the Peter Mandelson scandal. She accused the Prime Minister of “dishonesty mingled with weakness, evasion and contempt.”

Sir Keir will make a statement to MPs on Monday following the revelation that Mandelson was appointed UK ambassador to Washington despite failing the vetting process. Sir Olly Robbins, who was only weeks into his job as Foreign Office permanent secretary at the time, was sacked on Thursday as he had lost the confidence of Sir Keir and Foreign Secretary Yvette Cooper. He is expected to speak to the Foreign Affairs Committee as early as next Tuesday.

But Mrs Badenoch accused Sir Keir of blaming officials instead of accepting responsibility himself.

She said: “A real leader stands up for the country, puts the national interest first and takes the hits. Yet this scandal exposes a man who thinks only about himself. Starmer has sacrificed his staff, blamed the security services and sent ministers out to lie on his behalf.

“He is disloyal not just to his country, but to those serving beneath him. People can accept a leader who makes an unpopular call and stands by it; they loathe a leader who lets others take the fall while he clings on. Time and again, when things go wrong, it is always someone else’s fault. Starmer’s stock defence is ‘don’t blame me, I’m only the Prime Minister’.

“The hypocrisy is staggering. The Labour leader built his reputation on standards, rules, and truthfulness in public life. Yet the voters know that those rules – sacred for the rest of us – are optional when it comes to the powerful. This is dishonesty mingled with weakness, evasion and contempt.

“Authority does not just come from the title of Prime Minister. It is earned through the truthfulness and responsibility that Starmer lacks.

“He is either lying about what he knew about Mandelson’s appointment, in which case he is corrupting the office, or he is so lazy and incompetent that he is unfit to run the country.”

And she insisted Sir Keir must resign – because the scandal is putting the UK at risk.

Writing in the Mail on Sunday, Mrs Badenoch said: “We have a Prime Minister consumed by his own survival. And, while he hangs on, desperately, the country drifts. While he protects himself, decisions are delayed and problems fester.

“Starmer has no idea how to make this country better, which is why we are becoming a nation that simply manages decline instead of striving for greatness. It is not a future I will accept – and it is not the future this country deserves.

“This is not a moment for bland managerialism, or for leaders clinging to office while the country loses confidence. It is a moment for seriousness, for courage, and for a government with a clear sense of duty to the next generation.

“Starmer has misled Parliament over Mandelson, misled the country and is taking the public for fools. This is not just a political failure. It is a moral one: He has put our national security at risk, he has lost the right to govern, he should resign.”