Making his final appearance in the Commons as prime minister, Boris Johnson tendered some advice to his successor. Don’t break the laws that you yourself introduced to curb a deadly pandemic. Don’t lie to parliament. Don’t reduce government to a trashy carnival of incompetence, sleaze and mendacity. No, obviously, he said none of that. He instead offered this tip: “Focus on the road ahead, but always remember to check the rear-view mirror.” That was actually sound advice. The rear-view mirror of the next prime minister will be filled with a juggernaut-shaped, road-hogging, attention-craving, angry, bitter and menacing presence. Mr Johnson himself will be breathing down her neck. We know from every unrepentant word he has uttered since Tory MPs acted to evict him that he burns with vengeful resentment. We know that he sees himself not as the architect of his own downfall, but as the victim of ungrateful rats. “I won these fuckers the election,” he raged within his bunker when they moved against him. Having dreamt of a decade at Number 10, he has ended up as a three-year prime minister, which is even harder for his monstrous ego to endure because it is only half as long as David Cameron, his rival since they were denizens of the Bullingdon Club. “Hasta la vista, baby,” he signed off from the dispatch box, an unsubtle signal that he thinks he could contrive a Berlusconi-like return to power. When he formally surrenders the keys to the Queen on Tuesday, a large part of him will be thinking that this is not farewell to the premiership, but merely adieu. He will be encouraged by the thought that he has been written off many times before, only to stage comebacks everyone else thought impossible. The quest may well be a fantasy, but his pursuit of it will fascinate his party and the media in a way bound to distract and destabilise his successor. A man whose only loyalty is to himself will not care a jot about that. He has already played an instrumental role in the destruction of three Tory premierships, those of Mr Cameron, Theresa May and his own. I assume, as pollsters, politicians and civil servants all do, that the next tenant of Number 10 will be Liz Truss. Hers will be a premiership beset by perils from day one and he will have no compunction about exploiting her vulnerabilities if he thinks it serves his ambitions. He’s told friends that his first priority is “to put hay in the loft”. Under the arrangements made for ex-premiers, he will be entitled to claim £115,000 a year from the taxpayer. This will sicken many of those trapped in the savage jaws of the cost of living crisis. To him, it will be chicken feed. He spent the premiership moaning to pals that he couldn’t live on the salary and was up to his eyes in debt. Now he will seize the opportunity to make stacks of cash. Some of the money-making avenues taken by ex-premiers don’t look viable for him. The corporate world bores him and companies are likely to blench at the reputational risk of giving a board seat to a disgraced ex-premier. His memoirs could attract a massive advance; speculation has gone north of £1m. But politicians usually only turn to memoir writing when they have accepted that their race is run. He also owes a publisher a book about Shakespeare in which he can draw on his personal experiences of fratricidal struggles, treachery and illicit sex. The easy route to quick riches will be making speeches, especially to audiences in America, country of his birth. People have been prepared to pay a hundred grand to sit through an hour of Mrs May, so he ought to be able to fill his boots. He will revive his career as a newspaper columnist. The Telegraph, which he once described as his “real boss”, and the Mail, which campaigned ferociously to keep him at Number 10, are competing to provide him with a very well-rewarded and very high-profile bully pulpit. His new employer will not want to pay big money for opinion pieces blandly supportive of his successor. His paymasters will expect him to make mischief and he will want to stir it up to keep himself in the spotlight. One senior Tory predicts: “He will be goaded on by his acolytes to be oppositional.” He is well-practised at playing the prince over the water while subverting the Tory leader of the day. He combined being mayor of London and later a Conservative MP with writing a column for the Telegraph during the Cameron premiership. It was a cause of such constant nervous apprehension to Mr Cameron and his aides that they used to refer to it as “Boris’s weekly mind-fuck”. He will wish the new prime minister every success while aching for her to fail. To satisfy his vanity and secure what he sees as his historical reputation, he needs to be seen as the exceptional Tory of his generation, the only one capable of securing the party a big majority. He will want to cultivate two false narratives. One, that the battalions of troubles that will besiege his successor would not have been anything like as awful were he still in Number 10. Two, that he is a colossus brought down by pygmies. A lot of effort has gone into propagating the myth that the lion of Brexit and hero of Ukraine was stabbed in the back by scheming remoaners in the “deep state”, craven cabinet snakes and pusillanimous Tory MPs. It is utter baloney. But it is baloney for which there is an appetite within the Tory tribe. “My party can have a weakness for betrayal narratives,” remarks one former cabinet minister, observing that it took Tories more than a decade to get over the fall of Margaret Thatcher. This phoney but potent betrayal narrative has been allowed to flourish during the contest to replace him. At the outset, it was assumed that any successor would want to distance themselves from his tawdry regime in order to try to convince the country that a new prime minister represents a fresh start. Ms Truss has instead surrounded herself with Johnsonites and pandered to the rump of his worshippers within the Tory party by expressing frequent regrets that he was removed. This she may live to rue. There are lots of reasons to think that the notion of a Johnson comeback is delusional. He leaves office extremely unpopular with voters. The only recent poll he has topped was one on the worst prime ministers since the Second World War. However desperate things become for their party, Conservative MPs are probably not quite so unhinged as to give a second act at Number 10 to a man whose first so discredited their party. He has few genuine friendships at Westminster and some Tory MPs think he won’t have the stomach for brooding on the backbenches. There’s also a tension with his desire to amass wealth, because he will be obliged to declare all his extracurricular earnings so long as he remains an MP. Then there’s the investigation into whether he lied to parliament about Partygate. He sees this as a mortal threat to any hopes of a comeback. Having tried and failed to prevent the inquiry by the privileges committee, he has since sought to besmirch it by spinning that it will be a “kangaroo court”, even though a majority of its members are Conservative MPs and it is advised by a former appeal court judge. In his final weeks in office, Downing Street used public money to pay for a contentious legal opinion attacking the fairness of the committee’s proceedings. Labour calls this an attempt to intimidate and some senior Tories agree. “It is outrageous to try to nobble the committee,” says one former cabinet minister. “It’s very Trumpian.” The hearings are dangerous to him because they will take evidence from police officers, civil servants and himself – under oath. If he can’t prevent that, he will try to cast doubt on the legitimacy of a guilty verdict in the hope of persuading MPs to reject or soften any penalties the committee might recommend. Suspension from the Commons for more than 10 days would allow his Uxbridge constituents to petition for a byelection to throw him out. How she handles this will be an early test of the integrity and the savvy of Ms Truss. Any attempt on her part to stymie the investigation would ignite outrage and be taken as confirmation that she is Boris Johnson in heels. Her interests would be best served by his removal from the Commons. The road ahead is highly hazardous as it is. The last thing she needs is his predatory shadow in her rear-view mirror. Andrew Rawnsley is Chief Political Commentator of the Observer