Voices: The blunt truth is that Suella Braverman has next to no chance of becoming Tory leader

It was a mistake for Rishi Sunak to have appointed Suella Braverman as home secretary in the first place, said Gavin Barwell, Theresa May’s former chief of staff. Indeed, so said The Independent, in its editorial at the time.

Although it depends on your definition of “mistake”. As George Osborne, another former player turned commentator, often says, the first rule in politics is to know how to count. Sunak understood that he needed to cut some deals to get his hands on the levers of power. One of those deals was with Braverman, who could deliver a small but significant group of Tory MPs, the rump of the once-feared European Research Group of Eurosceptics, which she had chaired.

If only David Miliband had shown the same understanding in 2010, he could have saved the Labour Party a long detour. He should have done a deal with Ed Balls and offered him the post of shadow chancellor, which could have been enough to persuade the six MPs David needed to vote for him rather than his brother. But David wanted to win on his own terms. He realised that tying himself to Balls would have been a source of constant friction, replicating the Blair-Brown dysfunction for another generation. He should have done it anyway because that is how politics works, and it would have avoided the far worse dysfunction of Jeremy Corbyn’s leadership.

The same goes for Sunak. Obviously, all right-thinking people, including Barwell and (other) Independent readers, think that Braverman is a disaster as home secretary. But the alternative, 13 months ago, was Boris Johnson back as prime minister. By peeling off Braverman’s faction, Sunak ensured that the parliamentary Conservative Party would be a hostile environment for the former prime minister.

That was why Johnson folded. He had the nominations he needed to stand, and he would have been likely to win the ballot of party members, but with fewer than one-third of Tory MPs signed up to his cause, he knew that, as he said in his statement, “You can’t govern effectively unless you have a united party in parliament.”

Once Sunak was in No 10, however, he needed Braverman less. And once Johnson was out of parliament, in June this year, it could be argued that he didn’t need her at all. But Sunak continued to pursue a risk-averse policy of managing his parliamentary party. Braverman’s clique may be small, but he didn’t want to drive it into internal opposition if he could help it.

This week the numbers changed. After Braverman’s Times article, in which she referred again to “hate marches” and compared them confusingly to Northern Ireland, and then refused to make the changes Sunak demanded, it became obvious that it would be better for the government if she went than if she stayed. “If he doesn’t sack her, there will be a riot,” was one description I heard of the “soundings” of Tory MPs taken by the whips on Thursday.

She was never popular with the wider public but her comment about rough sleeping being a “lifestyle choice” caused dismay well beyond the soft-hearted Barwells and Grieves. What might be keeping Sunak from sacking her – apart from his irritating obsession with natural justice, procedure and propriety – is that he does not want to boost her campaign to be leader of the opposition after the election.

But now it is Braverman’s turn to know how to count. The fundamentals of the next Conservative leadership election have not changed. She needs one-third of MPs to support her to get on the ballot paper that goes to the party members. If her name is on the ballot paper, she has a chance of winning – although she is nothing like as popular with grassroots Tories as people think.

The latest Conservative Home survey of Tory members put her in fifth place among ministers attending cabinet, behind James Cleverly, Kemi Badenoch, Penny Mordaunt and Johnny Mercer.

Even to get her name in front of the members, however, she needs the votes of enough of her MP colleagues to put her in the top two. After the election, that is likely to be a smaller number than it was last time, but it is still a demanding target. She came sixth in last year’s contest, winning the votes of 32 MPs in the first round, a mere 9 per cent of the total, falling to 27 in the second round, when she came last and was eliminated.

Professor Tim Bale of Queen Mary University of London has analysed the ideological make-up of the parliamentary Tory party under a range of scenarios, and found that it doesn’t matter how many seats the Tories lose, the balance of MPs who supported different candidates remains about the same.

It is not a promising starting position for a Braverman leadership campaign, especially as her striking of poses does not appear to have added to her tally of supporters.

Her 15 public backers last year included Steve Baker and Sir Bernard Jenkin. But Baker “withdrew his support” earlier this year because of her language about grooming gangs – a sweeping statement that “British-Pakistani males … see women in a demeaned and illegitimate way”. Meanwhile, Sir Bernard this week said it was “most unfortunate that the chief of Met police is being placed under pressure from the government” in a WhatsApp message to fellow Tory MPs.

She may hope that, liberated from the constraints of collective responsibility (which never seemed to constrain her quite as much as other ministers), she will be able to set out a platform that will appeal to MPs and party members alike. My assumption is that, even if the government wins at the Supreme Court on Wednesday, few asylum seekers will ever be sent to Rwanda and the small boats will keep coming.

She may intend to fight for the leadership on a platform of repudiating the European Convention on Human Rights, but that is not a view that is shared by enough Tory MPs. It is foolish to predict what might happen in a leadership election that is still probably a year away (I was struck by US research suggesting that opinion polls this far out from next year’s presidential election have a predictive power of zero), but I would say that Badenoch, Cleverly and Mordaunt would all pick up more MPs’ votes than Braverman.

Badenoch’s pragmatism in refusing to sweep away all EU-based law has done her less harm with the Eurosceptics than Braverman hoped, and Badenoch’s distancing from Michael Gove over his affair with a married acquaintance of hers can only help her with the few remaining Nadine Dorries-ites who regard Gove with suspicion.

If Rishi Sunak is holding back from ridding himself of his troublesome home secretary because he fears boosting her leadership campaign, he shouldn’t. He knows how to count. He should do the right thing.