This is how likely a Conservative leadership contest now is – and who the candidates would be

Brexit Secretary David Davis would have a strong chance now but his moment would have passed by 2019. Conversely, the Home Secretary Amber Rudd would be a stronger candidate then than now. Boris Johnson could win among the members but the Foreign Secretary’s undermining of May has alienated many

We should take cabinet ministers’ pledges of loyalty to the PM with a pinch of salt (Getty)

Theresa May is hanging on to job by her fingernails, now that the not very secret plot to depose her by the former Conservative chairman Grant Shapps has become public.

Shapps claimed today that he had been outed by Tory whips. I doubt that very much; it was in their interests to dampen down the rebellion against May in the hope it would fizzle out, rather than talk it up. Although May loyalists hope that other MPs will now be deterred from joining in, it could go the other way.

Waverers might decide that it is better to bring matters to a head rather than let May stumble on. According to Shapps, 30 MPs want May to fall on her sword, including some ministers. He hopes to avoid a formal challenge. Under Tory rules, 48 MPs would need to call for a vote of confidence in May. If she lost that, she would be out and could not stand in the ensuing leadership election. But it is quite possible that she could win the confidence vote.

Shapps made sense when he argued that there is a window for a leadership contest before Christmas which would not really disrupt the difficult Brexit negotiations. Angela Merkel is preoccupied with forming a new coalition and the talks in Brussels will not move on to the long-term UK-EU relationship until the new year. If May is still PM in January, her party will have to stick with her, as a deal must be done by next autumn. Another hiatus would put an agreement at risk.

Although the Tory high command claims the Shapps coup has failed, the next few days will be crucial and May could yet be forced out sooner rather than later. She looked better today when she popped up in her Maidenhead constituency, insisting she was offering the “calm leadership” the country needs. While the last few days have been anything but calm, she may feel it is her duty to complete the Brexit process – especially as there is no obvious successor who could unite the party.

We should take cabinet ministers’ pledges of loyalty with a pinch of salt. They are hardly dispassionate observers, and will be weighing up their own career prospects. Timing is everything.

Of the potential runners, the Brexit Secretary, David Davis, would have a strong chance now but his moment would have passed by 2019. Conversely, the Home Secretary, Amber Rudd, would be a stronger candidate then than now, since the Tories’ 100,000 members, who elect the leader, are unlikely to install a Remainer who now supports soft Brexit.

Boris Johnson could win among the members but the Foreign Secretary’s undermining of May has alienated many MPs, who choose a shortlist of two for the ballot of party members. Johnson would now struggle to get on it. Ruth Davidson had a good Tory conference but could not run now as she is not an MP. The Scottish Tory leader and kickboxer would have to be dragged kicking and screaming into a 2019 contest because she wants to become Scotland’s First Minister in 2021.

Younger Tory MPs would want one of their own to enter a leadership race. Jacob Rees-Mogg, the pin-striped Brexiteer backbencher, is flavour of the month but I doubt Tory MPs would be mad enough to put him on the shortlist since Jeremy Corbyn would love to go head-to-head with him. (That would be a fun election).

If May survives, it will be because enough people in both the Tories’ soft and hard Brexit factions prefer to hold on to Nurse Theresa for fear of someone worse.

Shapps is far from alone in thinking that things cannot go on as they are. At the Manchester conference I was struck by how many Tories fear that May is tarnishing the party’s brand. It wasn’t about how she delivered her speech, but the Tories’ failure at the conference to spell out a vision to compete with Corbyn in the battle of values and ideas. “Her policy offerings were too small,” one loyalist cabinet minister told me.

Listening to the Tories debate how to reconnect with the under-45s, I concluded that May paid a price in June for ditching the social liberalism which helped David Cameron win a majority in 2015. Hard Brexit and an immigration target in which her Cabinet doesn’t believe will not woo younger voters with outward-looking, tolerant and liberal instincts.

May retained Cameron’s other tablet of stone – social justice – but has been slow to translate it into policy. “Theresa May’s rhetoric has not been matched by reality,” said Ryan Shorthouse, director of the Bright Blue liberal conservative think tank. The next Tory leader will need to go back to Cameron’s two planks.

To survive, May needs to do what she failed to achieve in Manchester and reassert her authority. She should have the courage to reshuffle her Cabinet to bring in fresh blood. She should make a big, bold, policy-rich speech. On the other hand….