MPs have got into the habit of regicide.

Four of the last six occupants of 10 Downing Street were dispensed with by their own parliamentary parties rather than the electorate.

Margaret Thatcher, Tony Blair, David Cameron and Theresa May never got the chance for a final appeal at the ballot box. They quit under threat from their own side in the Commons before the next general election.

John Major and Gordon Brown rode out near fatal challenges from rebels only to be kicked out when the people had their say at last in an election.

Boris Johnson’s premiership has reached the same precarious stage as his predecessors in record time. History does not repeat itself exactly but recent experience can give pointers as to the likely direction of travel.

Having reported on the rise and fall of all the above at close quarters I’ve been wondering which trajectory Boris Johnson is most likely to follow.

Why Boris Johnson comes off badly

To see clearly it is important not to be bamboozled by the claims and counter-claims being bandied about.

The fate of Thatcher, Blair, Cameron and May gives the lie to the argument made by his most vociferous supporters during the confidence vote this week. Based on past precedent, the fourteen million people who ‘voted for him’ in December 2019 – have not given him ‘a mandate’ to rule unchallenged until the next general election. Those four ex-prime ministers found that such assurances were for the birds.

Perhaps that is because the UK has a parliamentary rather than a presidential system. In cold figures only 25,351 people actually voted for Johnson personally, in his Uxbridge and South Ruislip constituency. All the rest backed other candidates standing elsewhere for the Conservatives.

You can read statistical analysis of Johnson’s performance compared to previous Tory prime ministers here.

Unlike the straight no confidence challenges faced by May and Johnson, Thatcher and Major fought leadership challenges, when there were other candidates and some MPs abstained, but all of them were judged in secret ballots of Tory MPs. This means it is possible to gauge how much support each of them had from their MPs.

Boris Johnson comes off badly. A concerted whipping operation run by senior allies and friends ensured that John Major got two-thirds backing, 66%, when he put his leadership on the line to see off the challenge from Eurosceptics, or as he put it infelicitously “the bastards”. There were fewer friends shilling for Johnson last Monday.

Theresa May enjoyed the confidence of 63% of her MPs, although that only bought her a few more months as prime minister. Johnson won his vote too, but with less support, 58.7%. Slightly more than two Tory MPs in five, 41%, had no confidence in his leadership. That puts him on a par with Margaret Thatcher’s grisly rating in the 1990 leadership contest.

How does Johnson compare to Thatcher’s final days?

How do the strengths and weaknesses of Johnson’s current position and the Thatcher endgame stand up?

Her disappointingly weak victory meant Thatcher faced a second round in the leadership contest. She said “we fight on, we fight to win” but was gone within days before it took place. Johnson has survived for now, with a technical immunity from a second challenge for a year.

There have been “no men in grey suits” – long-serving party grandees – discretely informing him that his time is up, and crucially, no cabinet ministers prepared to challenge him openly.

Johnson would have been finished on Monday, or come to that in January when partygate burst into the headlines, had Rishi Sunak, say, resigned in protest at his behaviour.

Thatcher’s fall was foretold before her last leadership challenge by the resignations of her chancellor Nigel Lawson and Sir Geoffrey Howe, who had served her as chancellor, foreign secretary and deputy prime minister. There is no-one of equivalent independent standing in Johnson’s cabinet. He purged many veterans who might have become threats not just from his government, but from the party and parliament too.

Could Jeremy Hunt be the rebel to end Johnson?

After announcing his vote of no confidence, Jeremy Hunt has at last emerged as a potential rebel leader outside government.

He may be a fellow self-made millionaire but he is no Michael Heseltine. Heseltine dedicated himself to campaigning against Thatcher and became the darling of the Conservative conference fringe with his rabble-rousing rallies, a bit like Boris Johnson in his years before becoming prime minister.

Hunt seems uncertain whether he really wants to take up the cudgels. Perhaps he calculates that he can never win.

The one thing he has in common with Heseltine, and, Ken Clarke, that other perennially available big beast, is that as a pro-European he appeals more to the country as a whole than to the Conservative activists who choose the leader.

Did Johnson get all the big calls right?

The second questionable line delivered by Team Boris is that “he got all the big calls right”.

This may or may not be true, but it is evidently not what they think themselves since they make clear, often in the same broadcast interview, that the price of their support is that he should “listen” and U-turn on some “big calls” he has already made such as raising taxes or pursuing net zero carbon emissions.

Policy divisions in Tory ranks may not be as dramatic as those faced by Thatcher, Major and May over such issues as Europe and the poll tax but it is wrong to say that Boris Johnson’s problems with his party are just over his personal behaviour.

Most Tory MPs want policy changes, often in opposite directions. Those Tory MPs who voted against him this week are not expressing contrition, just the hope Johnson will change.

When – not if – there will be another challenge

Senior parliamentarians are already speculating about rule changes to allow another no confidence challenge to the prime minister as soon as after the Wakefield and Tiverton by-elections on 23 June.

Others prefer to “wait for the autumn”, anticipating the standards committee will sentence Johnson to suspension from parliament for lying to it.

Contrary to the prime minister’s bold assertions this week, Monday’s vote is most unlikely to “draw a line” under criticisms of his leadership even in his own party.

As he battles to keep his MPs on side, their minds will also be concentrated on their own fates at the next general election. The defeats of John Major and Gordon Brown are not good auguries for parties who fail to dispense with a wounded leader.

Adam Boulton will be writing a column every Friday for Sky News