In a move that could mark the beginning of the end for the Prime Minister, the Health Secretary and Chancellor quit late on Tuesday evening just minutes after Mr Johnson had apologized for the Chris Pincher scandal.
Mr Sunak has suggested in his resignation letter to the Prime Minister that the Government is not being “conducted properly, competently and seriously”, as he told Boris Johnson that “our approaches are fundamentally too different”.
He wrote: “The public rightly expect government to be conducted properly, competently and seriously. I recognize this may be my last ministerial job, but I believe these standards are worth fighting for and that is why I am resigning.
“On those occasions where I disagree with you privately, I have supported you publicly.
“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.
“I recognize this may be my last ministerial job, but I believe these standards are worth fighting for and that is why I am resigning.”
The Health Secretary told Mr Johnson that the British people “rightly expect integrity from their Government”.
Sajid Javid wrote: “The tone you set as leader, and the values you represent, reflect on your colleagues, your party and ultimately the country.
“Conservatives at their best are seen as hard-headed decision makers, guided by strong values. We may not have always been popular, but we have been competent in acting in the national interest.
“Sadly, in the current circumstances, the public are concluding that we are now neither.”
He added: “I have spoken to the Prime Minister to tender my resignation as Secretary of State for Health & Social Care.
“The country needs a strong and principled Conservative party, and the party is bigger than any one individual.
“I served you loyally and as a friend, but we all serve the country first. When made to choose between those loyalties there can only be one answer.
“It has been an enormous privilege to serve in this role, but I regret that I can no longer continue in good conscience.
“It is clear to me that this situation will not change under your leadership – and you have therefore lost my confidence too”.
Boris Johnson ‘forgot’ about Chris Pincher groping claims, Downing Street says
Their decision was praised by the man who used to be in charge of Conservative Party discipline.
Former Chief Whip Mark Harper tweeted: “Tonight we have seen leadership from Rishi Sunak and Sajid Javid.
“Honourable decisions made by honorable men. The Conservative Party still has so much to offer to our country. It’s time for a fresh start.”
Earlier Sir Keir Starmer had directly called on ministers to resign.
Asked if Mr Johnson was a “pathological liar,” he said: “Yes, he’s a liar.
“What we’re seeing this week is a repeat of what we’ve seen so many times, which is Government ministers going out onto the airwaves, giving answers to questions, and no sooner have they finished the half round that the answers they’ ve given aren’t accurate because the Prime Minister and Number 10 haven’t been straight with them.
“That is not this week’s story, although it is this week’s story, it’s every week’s story. It’s on repeat, which is why you see the Conservative Party tearing itself apart today. Should his Cabinet members make sure he leaves office, yes they should. It’s their responsibility to him, in the national interest, to remove him from office.
“They know what he’s like, he’s said that he’s psychologically incapable of changing, and therefore they have to do what’s in the national interest and remove him.”
The Labor leader added: “They should resign, or force him to resign. They have to step up in the national interest now, otherwise they are nodding dogs in this.
“I would say to them directly: act in the national interest and resign.”
Sir Keir claimed “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 Labor 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. Backing him when he broke the law. Backing him when he lied repeatedly. Backing him when he mocked the sacrifices of the British people.
“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.”
Scottish First Minister Nicola Sturgeon said “the whole rotten lot” in Mr Johnson’s Westminster government should go.
She said: “Feels like end might be nigh for Johnson – not a moment too soon.
“Remarkable tho that the resigning ministers were only prepared to go when they were lied to – they defended him lying to public.
“The whole rotten lot needs to go. And needs the permanent alternative of independence.”
SNP Westminster Leader Ian Blackford claimed Mr Johnson’s government was collapsing.
He said: “This is the end for Boris Johnson. Tory MPs should have got rid of him months ago – and it speaks volumes they are only now acting out of self-interest and fear they will lose their seats at the next election.
“Westminster is in constant crisis. Whoever replaces Boris Johnson, Scotland will still be stuck with a Tory government we didn’t vote for imposing Brexit, austerity cuts and damaging policies we don’t support.”