Rishi Sunak does not intend to stay as Conservative leader beyond the summer, allies have said, amid a split in the party over how long it should take to elect a new leader. The party now faces the prospect of having to appoint an interim leader if the contest goes on for several more months, and several senior figures fear the hard-right populist Nigel Farage could position himself as de facto leader of the opposition if the battle drags on. Tory MPs including Iain Duncan Smith, Nick Timothy and George Freeman have said the party should take the process slowly, potentially lasting until the end of year. Sunak, who was forced to step down as prime minister when Labour won a landslide election victory last week, is understood to be willing to stay on until his party’s leadership election begins in earnest over the summer. But he is unwilling to stay beyond that, including for the October party conference and the expected budget. The former prime minister is willing to accommodate an orderly transition and to put in place plans to hold the new government to account, but believes it would be hard for him to continue to do that come the autumn. Sunak will put together a temporary shadow cabinet before the summer recess in order to respond to the Labour government in the House of Commons. Eleven Conservative cabinet ministers lost their seats at the election. Should a longer contest take place, the party might be forced to appoint another interim leader, potentially Sunak’s former deputy Oliver Dowden, or a grandee like the former party leader Duncan Smith. “That is a deeply undesirable situation,” said one MP. “Why would we mess around with an interim leader?” Another Tory said that a delayed contest would give Reform MPs such as Farage an “open goal” to position themselves as the opposition to Labour. However, a number of MPs believe the party must do a full audit of election data and conduct in-depth research before a contest can begin in earnest. Those MPs favour a process that does not even start until the party’s conference in October. Freeman, a former minister, told the BBC the contest should last at least six months. “I think it’s really important that we don’t rush into a leadership contest now. We have an honest six-months real appraisal of all the different voter groups we lost and why – not ‘What did Boris [Johnson] do wrong?’ or What did Liz Truss do wrong?’ – but ‘What are the voter groups we lost?’” he said. “I’d like this party conference to be a serious conference of renewal for ourselves and to ask those questions honestly.” Another former minister, Kevin Hollinrake, told GB News that the contest “should start in the autumn, probably September time, and pick a leader by the end of the year. I don’t think there’s any rush to do that.” The final timeline must be agreed by the remaining 121 Conservative MPs, with the hope of electing a new chair of the backbench 1922 Committee within days. The two remaining members of the committee, Geoffrey Clifton-Brown and Bob Blackman, will stand for chair. “One of the problems is that we literally don’t have a committee because all but two of them lost their seats – the two people tipped for chairman were Eddie Hughes and Mark Spencer and they lost their seats,” one senior Tory said. “So at the moment we can’t even start to put a plan in place.” Tories believed to be preparing bids to run include the former immigration minister Robert Jenrick, the former home secretary Priti Patel, the former security minister Tom Tugendhat and the former business secretary Kemi Badenoch. Suella Braverman, the former home secretary who has been a key figure on the right, is said by MPs to be losing support to Jenrick. Braverman will address the Popular Conservatism “Beginning the rebuild” conference on Tuesday via video link. All the key members of that Tory faction, Truss, Ranil Jayawardena, Jacob Rees-Mogg and Simon Clarke lost their seats at the election.