The former Mayor of London abandoned his dream of becoming Prime Minister at 11.53am, seven minutes before the deadline for nominations.
After setting out what would have been his manifesto for the Tory leadership, he said: “That is the agenda for the next Prime Minister of this country.
“But I have to tell you my friends, you who have waited faithfully for the punchline of this speech, that having consulted colleagues and in lieu of the circumstances in Parliament I have concluded that person cannot be me.”
In an oblique reference to Mr Gove as a backstabber, Mr Johnson quoted from Shakespeare’s Julius Caesar saying it was “a time not to fight against the tide of history but to take that tide at the flood and sail on to fortune”.
The original quotation was by Brutus, the friend who turned assassin.
The morning’s events left a room full of MPs, journalists and supporters who had come to see the launch of Back Boris 2016 in complete shock.
One of the most extraordinary days ever seen even by the standards of Westminster skulduggery began with a bombshell when Justice Secretary Mr Gove – who had agreed to be Boris’s campaign manager – withdrew his support exactly two and a half hours before launch press speech was due.
He issued a bombshell statement that savagely denounced the former Mayor of London as being not up to the job of Premier.
And Mr Gove announced he would be running himself for the job, and was immediately joined by Education Secretary Nicky Morgan and three ministers on the Johnson team, Nicholas Boles, Dominic Raab and Ed Vaizey.
As Mr Johnson’s shattered team including Lynton Crosby pondered their chances, friends railed against the “treachery” of Mr Gove. “Boris has been stabbed in the back,” said one.
She was relaxed and shrugged off her dour image with jokes and jibes at Mr Johnson, including his purchase of anti-riot water cannon that she banned from use.
“Last time he did a deal with the Germans, he came back with three nearly new water cannons,” she said, to laughter.
Mrs May stressed that her leadership bid did not require flaky deals or policy compromises.
Asked about her position, she replied: “My pitch is very simple: I’m Theresa May and I think I’m the best person to lead this country.”
The Gove bombshell exploded just after 9am.
His statement concluded: “I have come, reluctantly, to the conclusion that Boris cannot provide the leadership or build the team for the task ahead.
“I have, therefore, decided to put my name forward for the leadership. I want there to be an open and positive debate about the path the country will now take.”
Gove allies said the key cause of the breakdown was a column written by Mr Johnson in the Telegraph on Monday that suggested he wanted to compromise on a Brexit from the EU, suggesting that access to the single market was a bigger priority than curbing immigration.
Mr Johnson had refused to submit the column to his backers for advance checking.
To make matters worse, Mr Gove was told the fateful paragraph had been a “slip” because Mr Johnson was “tired”.
Other spats were over the handing out of jobs to right-wingers, seen as the litmus test of whether Mr Johnson could be trusted by eurosceptics.
Mr Raab said assurances of “turning a dream ticket into a dream team” had failed to materialise.
A leaked email from Mr Gove’s wife, Sarah, last night laid bare the tensions and lack of trust.
Friends of Mr Gove said he only decided late last night to jump off the Boris bandwagon after spending days fretting.
A Gove ally said: “He drew the conclusion over the week that Boris was not up to the job of being Prime Minister.”
In more dramas, Health Secretary Jeremy Hunt pulled out of the race and backed Mrs May. Ms Morgan dropped her own bid praised Mr Gove’s “skill and credibility … to renegotiate our exit.”
Energy minister Andrea Leadsom, a leading Leave player, and former Tory chairman Liam Fox joined Work and Pensions Secretary Stephen Crabb by launching bids of their own.
The spectacular Gove-Johnson fallout ended the partnership that changed the course of British history by persuading 17 million Britons to vote to withdraw from the European Union.
They transformed Vote Leave by combining Mr Johnson’s colourful showmanship with Mr Gove’s steely intellect. Many Tory MPs hoped they could do the same for the leadership.
In reality they were always the odd couple, whose friendship had been marred by rivalry and occasional feuding.
Mr Gove was once caught briefing media tycoon Rupert Murdoch that Mr Johnson was not up to the task of being Prime Minister, urging support for Chancellor George Osborne instead.
Weeks later they were seen enjoying themselves on the town after dinner.
The collapse of the Boris campaign followed other complaints from MPs that Boris’s image had been tarnished by his Brexit crusade.
One London Tory said: “I have had literally scores of emails saying Boris let London down by campaigning for Leave.”
In addition there were complaints about the way Mr Johnson was campaigning behind closed doors at Westminster. He pulled out of a hustings in front of 50 wavering MPs yesterday and MPs lured to talks in his office said they were surprised to find other MPs in the waiting room.
Mr Gove had in the past ruled himself out as a Tory leader. In today’s statement he said: “I have repeatedly said that I do not want to be Prime Minister. But events since last Thursday have weighed heavily with me.”
Wimbledon MP Stephen Hammond backed Theresa May, calling her “principled”. Campaign chief Alan Duncan said: “With Theresa what you see is what you get. She doesn’t do deals in smoke filled rooms.”