UK 29 August 2018 Why does nobody understand how a Conservative leadership election works? Talk of Boris Johnson challenging Theresa May and hard-right entryists electing him betrays a lack of knowledge of how a contest would actually work. Getty Once and future leaders? Sign UpGet the New Statesman's Morning Call email. Sign-up Is there anyone in the Conservative Party who knows how its leadership rules work? Not Theresa May, who has told the travelling press pack on her trip to Africa that she would fight a leadership challenge from Boris Johnson. "I am in this for the long term," she said in a statement of intent splashed by several papers today. "I am in this for delivering for the British people, and that’s what I’m focused on.” There is arguably plenty wrong with that answer but the real problem is the premise of the question. While a stalking horse leadership bid from backbench wet Anthony Meyer in 1989 set in train the downfall of Margaret Thatcher, the last woman Tory leader, no such mechanism exists today. Johnson cannot "challenge" May for the leadership. The only way the Tories can change their leader is through a confidence vote. It would take 48 letters to Graham Brady, the chair of the 1922 Committee, to trigger one. If May won, she would be granted a year's immunity from further challenge, if she lost, then she would be forced to resign and be barred from standing in the ensuing contest. Johnson, then, has no power to launch a leadership challenge save for corralling colleagues (not his strength) to demand a confidence vote, and hoping it goes his way (of which there no guarantee), so that he can stand against a field that doesn't include May (which would dilute his unique selling point as a singular corrective to her suffocating compromises on Brexit). Other misconceptions are taking hold too. Add to this the incipient hysteria over entryism from Ukip and the far right. It's true that there has been a pronounced spike in the Tory membership in recent months. There's also plenty of evidence to suggest that many of these new members are arriving, or returning, from Ukip and the Eurosceptic right with the aim of changing the party's course on Brexit. They could do this by deselecting MPs or by electing a doctrinaire Brexiteer as its leader and thus prime minister. The latter idea has been floated explicitly by Arron Banks, and again Johnson's name is the one in the frame. But the rather less exciting point this narrative glosses over is that these new members will not decide the two candidates they get to vote for. That job will be done by Conservative MPs. The chances of Johnson reaching the final round and capitalising on the love of members old and new that we keep being told exists are thus vanishingly small. The scale and intensity of opprobrium from his colleagues over his prevarication on Heathrow, his comments on the burqa and indeed his inauspicious exit from the 2016 leadership race prove that much. The only way he or Jacob Rees-Mogg or A.N. Other Hard Brexiteer will reach the final round is if the rules are changed to nobble MPs. Even Leavers with a tenuous relationship with objective reality, like Andrea Jenkyns, know this, which is why they have suggested it. None of this is to say that a Sajid Javid, Penny Mourdant or somebody else won't ride to victory by adopting the mantle that they think these new members want them to wear. Nor is it to downplay the need for any candidate with hopes of reaching the final two to have a serious offer to the likes of Jenkyns and other fundamentalist Brexiteers, who will be a crucial caucus. And there is every chance May will face a confidence vote sparked by discontent over Brexit soon, perhaps with Johnson as its parliamentary poster boy and new members acting as a catalyst. But what it wouldn't be is a Johnson leadership challenge, nor, in all likelihood, would it offer new arrivals a chance to elect him. Can we stop pretending otherwise please? › Belinda Bauer’s Snap, a rare Booker-longlisted crime novel, is uneven at best Patrick Maguire was political correspondent at the New Statesman. Subscribe For daily analysis & more political coverage from Westminster and beyond subscribe for just £1 per month!