Health minister Sajid Javid and chancellor Rishi Sunak tonight sensationally quit Boris Johnson's government.

Mr Javid said the prime minister had "lost his confidence" while Mr Sunak added: "I recognise this may be my last ministerial job, but I believe these standards are worth fighting for and that is why I am resigning.”

But tonight sources close to Liz Truss, foreign secretary and MP for South West Norfolk, said she was still backing the embattled PM.

In an incendiary letter, Mr Javid said the British people “expect integrity from their government” but voters now believed Mr Johnson’s administration was neither competent nor “acting in the national interest”.

Mr Sunak also suggested in his resignation letter to the prime minister that the government is not being “conducted properly, competently and seriously”, as he told Mr Johnson that “our approaches are fundamentally too different”.

He wrote: “The public rightly expect government to be conducted properly, competently and seriously. I recognise this may be my last ministerial job, but I believe these standards are worth fighting for and that is why I am resigning”.

He also said he had been “loyal” to Mr Johnson.

“On those occasions where I disagreed with you privately, I have supported you publicly," Mr Sunak added.

Mr Sunak also wrote: “In preparation for our proposed joint speech on the economy next week, it has become clear to me that our approaches are fundamentally too different.

“I am sad to be leaving government but I have reluctantly come to the conclusion that we cannot continue like this.”

The resignations came as Mr Johnson was forced into a humiliating apology over his handling of the Chris Pincher row after it emerged he had forgotten about being told of previous allegations of “inappropriate” conduct.

Mr Pincher quit as deputy chief whip last week following claims that he groped two men at a private members’ club, but Mr Johnson was told about allegations against him as far back as 2019.

The prime minister acknowledged he should have sacked Mr Pincher when he was told about the claims against him when he was a Foreign Office minister in 2019, but instead Mr Johnson went on to appoint him to other government roles.

Asked if that was an error, Mr Johnson said: “I think it was a mistake and I apologise for it. In hindsight it was the wrong thing to do.

“I apologise to everybody who has been badly affected by it. I want to make absolutely clear that there’s no place in this government for anybody who is predatory or who abuses their position of power.”

Sir Keir Starmer has said “it’s clear that this government is now collapsing” and said cabinet ministers who have resigned have been “complicit” as the prime minister “disgraced his office”.

The Labour leader said in a statement: “After all the sleaze, the scandals and the failure, it’s clear that this government is now collapsing. Tory cabinet ministers have known all along who this prime minister is.

“They have been his cheerleaders throughout this sorry saga.

“In doing so, they have been complicit every step of the way as he has disgraced his office and let down his country. If they had a shred of integrity they would have gone months ago.

“The British public will not be fooled. The Tory party is corrupted and changing one man won’t fix that.

“Only a real change of government can give Britain the fresh start it needs.”

Deputy prime minister Dominic Raab and home secretary Priti Patel are not expected to quit.

A source close to Mr Raab said he was “loyal” to Mr Johnson, while an ally of Ms Patel said “she’s staying”.