At the first stage of the Conservative leadership race, when Liz Truss was trying to win MPs’ support, her message was that she was the one who could ‘unite the right’. Now, her plan to survive in No. 10 relies on dividing the Tory left.

Regicide is a messy business. ‘It’s very hard to push her out,’ says a former cabinet minister. ‘We would need to change the rules. It could be seen as an establishment stitch-up. I think she needs to do the right thing and resign.’

Everyone in the Tory party agrees that there needs to be a unity candidate when Truss goes, but there is absolutely no unity on who that should be. ‘Until we know who to replace her with, we shouldn’t move,’ says a former government member. The Tories know the country cannot be subjected to another drawn-out leadership contest, so a new leader would be chosen either by an MPs’ vote – cutting out the broader party membership from the process – or by a coronation.

Some senior Tories have suggested establishing ‘a papal conclave’ whereby, in the same manner cardinals elect a pope, MPs would go into a room and not leave until a new leader has been selected. But MPs who are scarred by the last contest want a sense of who the successor is likely to be before they agree to take part.

Truss is betting her future on the fact the party won’t be able to unite around a candidate. Her allies believe that the Tory left poses a greater threat to her than the right. ‘The problem is they have a few candidates they could get behind – like Penny or Rishi,’ says a government aide. ‘But where does the right go? I don’t think they have many options. I can’t see a majority deciding their best bet is Suella.’

The threat from the left helps to explain why Truss chose Jeremy Hunt, a leading figure on the so-called One Nation wing of the Tories, as her new Chancellor. His appointment surprised many MPs, who had expected Truss to pick someone who had backed her in the leadership race as well as someone with Treasury experience (Nadhim Zahawi or Sajid Javid). Zahawi was considered, as was former business secretary Alok Sharma. But Hunt prevailed, and he has been given free rein on the condition he updates the Prime Minister regularly. In a bid to have friendly relations, the pair spent Sunday discussing economic plans at Chequers while their children played together.

In anticipation of a leadership challenge, Truss lost no time seeking to shore up support from the Tory left. She ducked parliament on Monday – accepting mockery and accusations of ‘hiding under a desk’ – so she could focus on other meetings, including an audience with the One Nation group of Tory MPs. She told them she was sorry for the political turmoil and that she understood helping those in need was a key concern – which is why, she said, she had promised the energy support package.

The One Nation MPs should, in theory, be the most desperate to depose Truss. Most of them backed other leadership candidates, and they were the most critical of her after her lacklustre appearance at the 1922 Committee last week. Yet Hunt’s appointment means that MPs who had been getting behind the idea of a Rishi Sunak/Penny Mordaunt joint ticket are reconsidering the need to act immediately. One MP who attended her One Nation meeting on Monday night says she was wooden and uninspiring but ‘at least she is visibly under Jeremy’s control’.

An unlikely praetorian guard has been established. Hunt allies such as Damian Green and Steve Brine are touring TV studios urging for calm and calling for Truss to be given more time. Hunt says he will not run for Tory leader again. So it is easy to see why his allies think this strange new arrangement between No. 10 and No. 11 is the next best thing. ‘Hunt is unsackable,’ says a government aide. How many One Nation Tories would risk moving against Truss now, when there’s a chance that a candidate such as Suella Braverman could run and win?

Then again, it’s far from clear how long Truss will stay as a prisoner of her Chancellor. The two fundamentally disagree on a great many things and there will soon be difficult decisions to be made on public spending cuts. In the past, for example, Hunt has rebelled over plans to cut foreign aid. Yet MPs on the right of the party view cuts to foreign aid as one of the more palatable ways to plug the fiscal hole. Ministers are already publicly threatening to resign if Truss U-turns on her defence spending promises.

So a leadership war could break out at any minute. Conversations over successors will continue. Sunak, Mordaunt, Ben Wallace and Boris Johnson are the most talked-about candidates. ‘I’d happily have Boris back if he’d do it,’ says one senior Tory who only five months ago said he had to go. (Even the One Nation group talk wistfully about Johnson’s campaigning skill.)

‘It has to be Rishi,’ says a member of the 2019 intake. ‘It’s the only option that will send a signal to the markets and give the party a chance at the next election.’ But other MPs have started talking of a ‘Sunak coup’ against Truss, accusing his former backers such as Mel Stride, Michael Gove and Gavin Williamson of working against the party’s interest by not accepting Truss’s victory from the start. Stride has been hosting meetings in his office to speak to like-minded MPs over food and drink. ‘Mel’s office is basically a bistro,’ says a senior Tory. ‘I can handle the plotting, but not the noise,’ complains one MP with a nearby office.

Tory leaders can stagger on for some time after being mortally wounded, as Theresa May and Johnson showed. The same factors may mean Truss is safe until her party unites around a better option. Factionalism is devastating for the party, but for now division remains Truss’s best hope for survival.