The explosively public political bust-up between Boris Johnson and Michael Gove was almost as unexpected as the Brexit referendum result they had brought about together.

Both men had driven the now legendary Brexit bus to the surprise destination of success in June 2016 and were plotting their next journey,  to Downing Street.

With David Cameron’s premiership buried under the rubble of Brexit, Mr Johnson would become prime minister and Mr Gove, his campaign manager, would-be chancellor.

Cabinet meeting
Environment Secretary Michael Gove and then foreign secretary Boris Johnson arrive for a Cabinet meeting (Stefan Rousseau/PA)

But it did not turn out quite like that.

In the tense and politically tumultuous days that followed the shock Brexit triumph, Mr Johnson largely disappeared from public view as the weight of victory descended upon the two men.

Mr Gove began to harbour growing doubts about the suitability of his ally for Number 10 as he also listened to whispers from colleagues that maybe he would be the better suited of the pair to be prime minister.

The first signs of unease broke into the open when a private email to Mr Gove from his columnist wife Sarah Vine was splashed across the newspapers.

Effigies of Prime Minister Theresa May, former foreign secretary Boris Johnson, Environment Secretary Michael Gove and former Brexit secretary David Davis (Isabel Infantes/PA)

The email read: “One simple message: you must have specific assurances from Boris otherwise you cannot guarantee your support.

“Do not concede any ground. Be your stubborn best.

“The details can be worked out later on, but without that you have no leverage.”

What was then supposed to be the glorious formal launch of Mr Johnson’s leadership bid turned out to be his humiliating public exit from the race for the Tory crown.

EU referendum
Michael Gove and Boris Johnson in happier times (Stefan Rousseau/PA)

Mr Gove suddenly withdrew support and announced his own intention to take the keys to Downing Street because he believed the man voters across the country knew simply as Boris was just not up to the job.

That decision sealed the leadership fates of both men as Mr Johnson slunk away from the scene abandoned and attacked by his closest political ally, and Mr Gove never recovered from being branded a back stabber.

The bitterness between the two camps was exemplified when a close supporter of Mr Johnson used Mr Gove’s love of the TV adventure Game Of Thrones to taunt him.

Mr Gove always likened himself to shrewd political strategist Tyrion Lannister  in the show, but the Boris backer wrote in an email: “He is actually Theon Greyjoy, or will be by the time I am finished with him.”

Priti Patel, Michael Gove and Boris Johnson (right) on the Vote Leave campaign bus in Lancashire (Stefan Rousseau/PA)

Theon Greyjoy famously had his penis cut off in one of the goriest scenes of the blood drenched drama series.

Theresa May then banished her former Cabinet sparring partner Mr Gove to the backbenches while promoting Mr Johnson to the sumptuous surrounds of the Foreign Office.

Both insist they have moved on since the momentous fall-out of June 2016, but have still exchanged sniper fire in the opening skirmishes of the latest lunge for Downing Street.

A run-off in the race for the Tory crown would be bound to see at least some of the bitterness of their political break-up boiling back to the surface.

The pair who helped navigate the Brexit campaign are no longer fellow travellers (Stefan Rousseau/PA)

A source in Jeremy Hunt’s camp said: “Boris and Michael are great candidates but we have seen their personal psychodrama before: it’s time to offer the country someone the EU will actually talk to.

“Jeremy is the candidate who can best unify the party and deliver Brexit.”