Even those of us who write about how ruthless the Tory party is are standing, staring, open-mouthed at what has just happened. At 9am this morning, Boris Johnson was pretty sure that he was going to become Prime Minister, or at least make the final two in the leadership contest and be in with a 50-50 chance. Then, at 9.02am an email landed that signalled he was done for, ruined. Johnson had no warning – no call, no text – from Michael Gove that he was about to declare Boris unfit to be Prime Minister and run himself. The explosive email went to reporters direct. Inside Team Boris there was astonishment, although some had suspected something was wrong earlier in the week.

What happened? Here, as I understand it so far, is what happened, although this episode will keep political historians in business for decades to come.

The post-referendum deal between Johnson and Gove was that Gove would become Chancellor and lead negotiator in the talks with the EU that will lead to Brexit. But there was a problem. Although the two men and their teams had worked together closely in the Leave campaign, the Johnson leadership campaign – which was quite distinct, and lying in wait for the outcome of the referendum – included Remainers who had been on the other side. There was a particular animus towards Dominic Cummings, Gove’s friend and trusted aide. Cummings was – along with Matthew Elliott – the mastermind of the Leave effort. Matthew is unfailingly polite and considerate. Cummings is – how can one phrase this? – a clever man who can be an acquired taste.

Some of Johnson’s team even said there must be no place for Cummings at the Team Boris table. This seems to have angred Gove. “Boris needed to win over Remain MPs, and Cummings was a non-starter for them. Toxic.”

Johnson’s leadership campaign has been no secret in recent years, but the operation to win over MPs has actually been conducted pretty undercover, with dinners and drinks, news of which did not leak, or not too much anyway. ‎Now, out of the two operations, a new Boris operation was patched together and it was not a happy operation. Boris Johnson’s friend and campaign chair Ben Wallace MP was joined as co-chair by Gove.

Gove’s aides and MPs he had brought to the Boris side turned up asking for the full list, the vital spreadsheet containing all the pledges of MPs. By this week Boris had more than 90 firm pledges, but in the uneasy atmosphere of the weekend and early this week, things started to go badly wrong. Boris’s column for the Telegraph was all over the shop. It was a disater, although it was seen by Gove, and he made amendments before it went to the Telegraph.

There was then a string of bizarre leaks. Boris had offered Osborne the post of Chancellor. No, he had not, say Boris’s friends. The pair had not spoken. There were other leaks that spooked Team Boris and Sir Lynton Crosby, the kingpin strategist who had turned up to run the Boris campaign. Crosby, say friends, has a low opinion of the Chancellor. He once told friends that Obsorne “could not strategise his way out of a paper bag.” Osborne, Gove’s friend, in terms of this Gove operation seems to have strategised pretty well this time, although I doubt anyone in this drama can ever trust anyone else ever again. Will Theresa May if she wins ever trust Osborne and Gove? I wouldn’t bet my house on it.

Then this morning, with the Boris spech written and ready to go, at 9.02am the bombshell email from Gove to reporters landed and then hit Twitter. Almost instantly around forty Tory MPs switched straight to Gove. It was almost as though it had been planned…

“Never seen anything like it. We had been cleaned out. There was a cuckoo in the nest,” says a Boris loyalist. The man himself is crushed and disconsolate. A lifetime of pretending to be a shambles, while preparing for the premiership, leads him to a set of circumstances that would even have foxed Churchill.

‎There will I am sure be other perspectives on this remarkable day. I merely report all this in a spirit of “first draft of history” and all that.