The defiant prime minister is now stepping down after a raft of resignations from his government in the last few days.
Recently-appointed chancellor Nadhim Zahawi told Boris Johnson this morning: “You must do the right thing and go now", as his refusal to accept that he has lost the trust of Conservative MPs has triggered another wave of ministerial resignations.
The Cabinet minister, who was only appointed to the role this week, tweeted an image of a letter with the caption; “Prime Minister: this is not sustainable and it will only get worse: for you, for the Conservative Party and most importantly of all the country. You must do the right thing and go now.”
Meanwhile, Brandon Lewis quit his Cabinet post as Northern Ireland Secretary, telling the British Prime Minister the government requires “honesty, integrity and mutual respect” and it is “now past the point of no return”.
His departure was soon followed by a string of other ministers as the number of MPs quitting government and party posts since Tuesday evening topped 50.
Helen Whately quit as a Treasury minister, telling Mr Johnson: “I have argued that you should continue as Prime Minister many times in recent months, but there are only so many times you can apologise and move on. That point has been reached.”
Damian Hinds resigned as security minister, telling Mr Johnson there has been a “serious erosion” in standards in public life and “faith in our democracy and public administration”.
He said on Twitter: “It shouldn’t take the resignation of dozens of colleagues, but for our country, and trust in our democracy, we must have a change of leadership.”
Science minister George Freeman wrote to the Prime Minister to say he no longer has confidence in his leadership.
In his resignation letter, he told Mr Johnson “the chaos in your Cabinet and No 10 this month is destroying our credibility” and “it can’t go on”.
Guy Opperman left his role as pensions minister, telling Mr Johnson that “recent events have shown clearly that the Government simply cannot function with you in charge”.
Technology minister Chris Phiilp has also resigned this morning, saying the “PM should step down given public and Parliamentary confidence has clearly gone, and given the importance of integrity in public life”.
James Cartlidge has also quit as courts’ minister, telling Boris Johnson: “The position is clearly untenable.”
And Education Secretary Michelle Donelan has resigned as well.
Despite the exodus from his government and a delegation of Cabinet ministers telling him he should go on Wednesday, Mr Johnson remains in office.
Because of his refusal to resign, the prime minister faces the prospect of another confidence vote, orchestrated by the Tory 1922 Committee of backbench MPs.
A new executive for the committee will be elected next Monday and could change the leadership rules, allowing for another confidence vote just a month after the last one – which the Prime Minister is expected to lose given the way MPs have deserted him since Tuesday.
While Mr Johnson remains in post, jostling for the leadership has already begun.
It can also be revealed that the UK government whips office has calculated Mr Johnson would win the support of just 65 Tory MPs in a confidence vote, from a total of almost 360.
Attorney General Suella Braverman is still in the role despite calling for the Prime Minister to quit and saying she will stand in the contest to replace him.
The departure of Mr Lewis means four Cabinet ministers have quit – Simon Hart resigned as Welsh secretary on Wednesday night, while chancellor Rishi Sunak and health secretary Sajid Javid stepped down on Tuesday, triggering the leadership crisis.
Michael Gove was fired as communities secretary, with No 10 sources describing him as a “snake” who had briefed against Mr Johnson.
The point-blank refusal to accept the pleas of his own Cabinet ministers to quit was a stark difference to Margaret Thatcher, who agreed to step down after Cabinet pressure in 1990.
The stand-off was unlike anything in modern British political history, with Theresa May and Tony Blair having agreed to leave office after mounting criticism within their party in recent decades.
Priti Patel, the Home Secretary, Nadhim Zahawi, the Chancellor, and Chris Heaton-Harris, the Chief Whip, were among the Cabinet figures who told Mr Johnson he had lost the support of his party. More than half a dozen cabinet figures made that argument.
Simon Hart, the Welsh Secretary, and Brandon Lewis, the Northern Ireland Secretary, both were prepared to resign but held back to confront Mr Johnson. Last night they were both on resignation watch.
In total 42 Tory MPs have resigned from official positions in the last 48 hours. That included 17 government ministers quitting, 14 yesterday.
Graham Brady, the 1922 Committee chairman, yesterday told Mr Johnson that a second vote on his leadership could happen as early as next week, with a new 1922 executive voted in place on Monday and free to change the leadership rules on Tuesday.
One Johnson ally said: “The prime minister has been saying the choice is not ‘me or not me’. The chance is to have a new PM and Chancellor spell out a new economic programme and a proper Conservative government.
“The alternative is pressing the button for three months of chaos as the party tears itself apart with no mandate. Labour will immediately demand an election, which this party will lose given the ‘coalition of chaos’ between Labour and the SNP and possible break up of Britain.”
The source summarised the message to Tory rebels as: “Stop thinking ‘this is Boris or no Boris’, or ‘topple Boris and this is all over’. Stick with this PM and a new Chancellor with a new economic programme. That is what is called for.”
Not everyone in the Cabinet turned on Mr Johnson yesterday. Both Jacob Rees-Mogg, the Brexit minister, and Nadine Dorries, the Culture Secretary – two of Mr Johnson’s most loyal supporters – rushed to Number 10 to urge him to stay.
Figures close to cabinet ministers Liz Truss and Ben Wallace, who were travelling, declined to say whether they urged Mr Johnson privately to go.
Mr Zahawi also did not quit last night, despite warning the prime minister of the perilous political position. He was back in the Treasury and was working with Number 10 on a speech on a “new economic plan”, which will include tax cuts.
Mr Gove did tell Mr Johnson to resign. He held a five minute one-on-one meeting with the prime minister yesterday morning where he urged him to quit on his own terms before it was too late.
Downing Street critics pointed the finger at Mr Gove after four figures in his department quit yesterday afternoon, fuelling calls for Mr Johnson to go.
An ally of Mr Gove denied he was plotting and said he would “100 percent” not stand to be Tory leader if there was a contest.
Throughout the day a succession of ministers and parliamentary private secretaries resigned, many tweeting out letters with excoriating views of the prime minister.
Mr Johnson also had to endure two Tory MPs calling for him to go during Prime Minister’s Questions, after which he sat with his arms crossed as Sajid Javid, his former health secretary who quit on Tuesday, gave a speech in the Commons calling for the cabinet to act.
Yet during a two-hour grilling before the Liaison Committee, Mr Johnson declared he was having a “terrific” week and insisted his government was pushing ahead with “ever increasing energy”.
There were signs last night of the mass resignations making government difficult, with planned scrutiny of a piece of legislation with MPs cancelled because the minister in question had quit.
If Mr Johnson remains in post by early next week, rebels predicted the 1922 Committee will force a second leadership vote to oust him that way.