Prospective Conservative party leadership candidates are preparing for a speedy contest to appoint a successor to Rishi Sunak by the autumn in an effort to challenge the rise of Reform. Potential contenders among the heavily depleted Tory ranks have already started organising their campaigns ahead of an expedited process to install a new leader, after the party crashed to its worst election result in history. Senior party figures are concerned that a drawn-out leadership contest would benefit Nigel Farage’s insurgent rightwing Reform UK and allow Labour to set the narrative about the Tory record in government, two well-placed Tory sources said. “There’s a deep-rooted fear within the party institutionally that if we don’t have a full-time leader by September, that will allow Farage to position himself as the main opposition to Starmer,” a Tory close to HQ said. “If you wait until party conference or even Christmas, the problem is you then come in as leader and instead of facing Starmer … you’re suddenly having to first argue with Farage.” Two sources said Sunak had indicated he would stay in place as a caretaker party leader until early September or potentially later into the autumn if needed. Another party figure said senior Conservatives were mindful of what happened in 2010 when David Cameron and George Osborne, newly installed in Downing Street, demonised Labour’s record while the opposition party was going through a protracted leadership battle. The source said Sunak would be prepared to face Keir Starmer at prime minister’s questions while a contest was ongoing and felt he had areas to challenge Labour on, including the cancellation of Rwanda deportation flights, upcoming decisions on public sector pay, and on defence spending. They said Sunak was committed to staying the course and would serve however the party wanted him to. In his resignation speech in Downing Street, Sunak confirmed he was standing down as Conservative leader but would stay in place while his replacement was elected. A third party source said there was an opposing push for the contest to take place over a longer period, allowing candidates to pitch themselves to the grassroots membership in a “beauty contest” at the Conservative conference in early October. Graham Brady, the outgoing chair of the 1922 Committee, who remains a member of the Conservative party board, is understood to be working out how a contest can be held under the current rules and what the next steps will be. To kickstart the formal process of choosing a leader, Conservative MPs must first elect a new chair and executive of the 1922 Committee, which represents Tory backbenchers. Geoffrey Clifton-Brown, a veteran Tory MP who has been a member of the committee’s executive, is seen as a favourite to replace Brady. This process is likely to take place by mid-July, and if the leadership contest is expedited then the parliamentary stages could be concluded by the end of the month, with two candidates put to a vote by grassroots members in August. The Conservative parliamentary party now has just over 120 members and appears to be fairly balanced between left and right. Centrist MPs from the One Nation caucus look likely to play an influential role, with Alicia Kearns, Caroline Nokes, Andrew Mitchell, George Freeman and Simon Hoare among those re-elected. Veteran rightwingers including Iain Duncan Smith and David Davis have also been re-elected. Jeremy Hunt, the chancellor, is likely to be an influential voice in shaping the future of the party after he unexpectedly saw off a challenge from the Liberal Democrats to hold his seat. Leadership contenders are expected to include: James Cleverly, the former home secretary; Kemi Badenoch, the former business secretary; Robert Jenrick, a former immigration minister; and Priti Patel, another former home secretary. One Nation MPs tipped to seek the top job are Tom Tugendhat, the former security minister, and Victoria Atkins, the former health secretary. Penny Mordaunt, the former Commons leader, and Grant Shapps, the former defence secretary, had both been expected to run but lost their seats in the Tory bloodbath. In their concession speeches, both warned their party not to swing to the right to try to counter the threat from Reform. In the wake of their defeat, party figures have been arguing about the wisdom of trying to win back voters who switched to Reform either with rightwing policies or by presenting a broader vision to reclaim the centre ground.