Looking back on the 1990 ousting of Margaret Thatcher as Conservative prime minister, her chief whip Tim Renton concluded that Thatcher had lost power because she “had ceased having an open mind” about how to unify her party or to govern. “She only wanted to have her own friends around her and she had come to identify No 10 and the job of prime minister with herself,” wrote Renton. “Anyone who stood in her way … was to be dispensed with. They were not of the right faith.” Boris Johnson is not in the same league as Thatcher as a successful prime minister and much else. She lasted 11 years in Downing Street and won three general elections. He has been prime minister for two and half and has won just once. She possessed ideological conviction in spades. His only serious interest is in himself. Yet all the evidence from the so-called reboot of Johnson’s government in the wake of the lockdown party scandals is that this prime minister is now making many of the same mistakes that Thatcher did more than a generation ago. Like her, Johnson surrounds himself with flatterers. Like her, he has come to identify the Conservative government with himself rather than the party or the electorate. Like her, he ostracises those who are not true believers – which in this case means believers in him. There are, of course, some differences. Yet the outcome will be the same. It would be hard to exaggerate the damage that ‘partygate’ has already done to Johnson. You can measure this in lots of ways: the drip-drip of backbenchers losing confidence, the mostly quiet (so far) ministerial resignations and departing advisers, and in the bad headlines – another photograph emerged today showing Johnson at a December 2020 party with a bottle of champagne. Never forget that, lurking in the wings, there is potentially the most threatening factor of them all: the police investigation into Downing Street parties and No 10’s false denials. Yet the most important evidence of how bad things have become is already in plain sight in election results and opinion polls. Johnson’s poll ratings today are truly dire. Indeed they are even worse today, in early February, than they were as recently as December, when the Conservatives suffered the humiliating loss of the North Shropshire byelection with a swing of 34% to the Liberal Democrats. According to Ipsos Mori polling, 65% of voters in Britain were already dissatisfied with Johnson back in December; today that figure stands at 70%. Even among Tory voters – of whom there are fewer to pick from now than before – dissatisfaction with Johnson went up from 28% to 34% in the same period. Another Ipsos Mori poll, conducted only a week ago, found just 14% of all voters think Johnson is an honest person (72% think he is not), while a mere 18% say he is a prime minister they can be proud of. He trails both Keir Starmer and Rishi Sunak on one leadership yardstick after another. These are polling and voting figures from which leaders do not come back. The Conservative donor John Armitage is right that Johnson has not just lost moral authority – as these polls confirm. He has also lost his touch. But Johnson is also losing votes. The crunch moment is now the local elections on 5 May, in which the Tories are defending some previously strong performances when these seats were last contested, but in what is now a far more ominous political environment. One of Johnson’s “senior advisers” in No 10 was quoted in last Sunday’s papers as saying: “He’s making very clear that they’ll have to send a Panzer division to get him out of there.” This is recognisably the sort of overblown language that Johnson would use as he battles to hang on to his prime ministership. But it is also recognisable evidence of a state of denial about how the rules of politics – and of real life – tend to work. When Johnson has to go, it will not involve a tank division in Downing Street. It will happen for one of three reasons – because of law-breaking, electoral defeats or ministerial resignations (Sunak’s in particular) – or some mix of them. Johnson will try to brazen it out. But in the end all routes will lead through the parliamentary party. Even if Johnson survives a vote of confidence, he will not be able to continue long. Thatcher won the first round in 1990, but the tide against her was too strong. The same would happen today. This week’s reboot and reshuffle do precisely nothing to alter this. That’s partly because they were overshadowed by the fallout from Johnson’s incendiary comments about Jimmy Savile. But it is also because they involve such minimalist, low-key changes. Even sympathetic observers see this as rearranging the furniture. There is no real strategy there, beyond survival, and even that looks fragile. A whips’ office purge of the kind Johnson carried out this week is a particular sign of weakness. It squanders a lot of accumulated knowledge about the party’s MPs, which will not help an embattled prime minister facing a very divided party. Reshuffles without sackings show a prime minister who is afraid of his MPs. That the only policy-related job in the reshuffle – Brexit promotion – should go to Jacob Rees-Mogg suggests that Johnson’s main concern is to solidify his support on the Tory right. Johnson is now governing from one day to the next, making it up as he goes along. He is good at creating distractions – the technique is at the core of his politics – but he needs a lot of them to survive. Last week’s flurry of ministerial policy announcements was part of that. So was the reshuffle. A possible end to Covid restrictions, another pander to the Tory right, distracted from today’s potentially difficult prime minister’s questions. Today a trip to Poland will do the job. Hints of a bigger reshuffle in the summer may help keep ambitious MPs in line. A recess next week may gain Johnson a brief breathing space. There will be plenty of propaganda informing us that No 10 is feeling more assured about the future. It will all be worthless. A prime minister who tries to hide in the bunker is ultimately doomed. In the end, MPs care more about their seats and their party than they care about a particular prime minister. That was what 1990 showed. The same thing will happen here, though we may have to wait until May. It could prove to be the one and only instance in his life in which the rules really will apply to Boris Johnson. Martin Kettle is a Guardian columnist