As Labour takes the lead in the opinion polls, the row over MPS’ second jobs has inflicted some damage on the prime minister

Dominic Cummings walked out of 10 Downing Street a year ago, as the prime minister said he could hear the “toot of the bugle of the scientific cavalry” as, armed with vaccines, it came over the hill to rescue him.

It was a chance for Boris Johnson to rebrand himself, which he seized with some success. With Cummings gone, he could restore relations with journalists, ministers, backbench Tory MPS and the civil service.

For most of the past year, Johnson has been living his best life, buoyed by vaccine euphoria in the opinion polls and chuntering on about “levelling up”. Meanwhile, all the atempts by his former chief adviser to destroy him, with colourful accounts of prime ministerial chaos in handling the early and middle phases of the pandemic, have let the target completely unmarked.

It is almost as if the prime minister has said: “If anyone is going to destroy me, I’ll do it myself.” Thus it was that he asked Conservative MPS to vote against the punishment of Owen Paterson for paid lobbying. As his majority collapsed from 80 to just 18, Johnson realised he had made a mistake, so he ordered a U-turn and demanded to know which fool had advised him that this was a clever thing to do.

Without an all-powerful adviser such as Cummings to take the blame, however, the buck stopped on Johnson’s desk, where it duly blew up, leaving the prime minister blinking through the soot like a cartoon character.

We have now reached the significant point in the evolution of public opinion known as “The Crossover”, where the polling averages switch from small Tory leads to small Labour ones. We shouldn’t exaggerate the effect of two weeks of daily headlines about the outside interests of Tory MPS. A lot of voters are not that interested, and for many people all it proves is that “they’re all the same”.

It may also be that other issues are important: the state of the NHS, the prospect of a tax rise, and the visible arrival of people in small boats across the Channel.

Nor is level-pegging in opinion polls, two and a half years before the likely election in May 2024, something that a governing party should worry about unduly. But worry it will. There are two groups of people who are liable to overreact to The Crossover: Tory MPS and Labour MPS. Tory MPS are likely to panic, and some Labour MPS at least are likely to allow their contempt for Johnson to cloud their judgement.

Both groups tend to subscribe to the “sudden collapse” theory of the prime minister’s electoral base: they both think that Johnson is so disorganised and incompetent that, once things start to turn against him, he will make more mistakes and alienate more people until the walls start falling in on themselves.

It is an interpretation assiduously promoted by Cummings, who celebrated the anniversary of his departure by publishing a blog post explaining again the uselessness of “the trolley”, as he calls the prime minister. As ever with Cummings, it is a brilliant combination of insight and wishful thinking.

He points out that Johnson’s threat in EU negotiations to suspend the Northern Ireland protocol is unlikely to work. He pours a justified bucket of cold water on the idea that it is all a cunning plan to “keep reviving Brexit to keep Labour off balance” — “we said we’d get Brexit done; the idea that arguing about Ireland is what key voters want to see is so dumb”.

Which is interesting, because it seems like the kind of aggressive, disruptive tactic Cummings might have advocated — and because he knows David Frost, the Brexit negotiator, well.

Cummings also points out the hypocrisy of Johnson’s U-turn on MPS’ outside interests, now that the prime minister says it is “crucial” that MPS follow the rules, telling them to “put your job as an MP first and devote yourself primarily to your constituents”.

He says that Johnson, ater winning the election and before coronavirus struck, said he found the job of prime minister “like geting up every morning pulling a 747 down the runway” and wanted to “spend a lot of time writing my Shakespeare book”.