Tory grandees including David Cameron are pushing back against the idea of a swift Conservative leadership contest, saying they want the candidates to be tested. Robert Jenrick, Kemi Badenoch, James Cleverly, Suella Braverman, Tom Tugendhat, Priti Patel and Victoria Atkins, are among the long list of names believed to be preparing possible bids. The contenders are readying themselves for a speedy contest to appoint a successor to Rishi Sunak by the early autumn in an effort to challenge the rise of Nigel Farage’s Reform UK party. But senior figures are pushing for the contest to take place over a longer period to allow candidates to pitch themselves to the grassroots membership in a “beauty contest” at the Conservative conference in early October. The former Conservative chancellor George Osborne said on Friday that Cameron was part of a “big effort … to get Rishi Sunak to just delay the moment when the new leader is chosen”. He said: “The contest can start, but it doesn’t have to conclude. It’s very important, because these people, these candidates, they’re all government ministers who have now been kicked out of office. None of them have been in opposition. “None of them have proved their mettle. I think over the next few months, it’s essential, and I know David thinks this and others do too, we just see how these candidates now perform on the opposition benches and use the party conference in the same way that Michael Howard did, to his eternal credit, in 2005.” Osborne, speaking on his Political Currency podcast with his former Labour opponent Ed Balls, said: “Above all, an opposition politician, an opposition leader, needs to be a communicator, and we don’t want a dud who may have excited some faction of the right in government or said the right thing on this particular bit of Brexit policy two years ago in the cabinet. “We want to know if these people can perform. Rishi Sunak … His last great service to the Conservative party would be to delay the Conservative contest’s outcome.” BBC Newsnight also reported that the former Conservative leader Iain Duncan Smith was in this camp. Others in the party are concerned that a drawn-out leadership contest would benefit 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 the party 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.” However, other people in the Conservative party are worried about having a vacuum in the leadership while Labour embeds itself in government and shapes the anti-Tory narrative. Many contenders have also already started organising their campaigns, after the party crashed to its worst election result in history. But Jeremy Hunt, the former chancellor who previously ran as a leadership hopeful, ruled himself out of the race, telling GB News that the “time has passed”. And asked whether she would be the next Tory leader, Braverman told broadcasters outside her home on Saturday: “No announcements. We’ve just got to take our time, we’ve got to figure out what the situation is. It’s been a really bad result. There’s no two ways about it. Hundreds of excellent Tory MPs have been kicked out of office.” Two sources said Sunak had indicated he would stay in place as a caretaker party leader until early September or later into the autumn if needed. Another party figure said senior Conservatives were mindful of what happened in 2010 when Cameron and 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 continued and felt he had areas on which to challenge Labour, including the cancellation of Rwanda deportation flights, decisions on public sector pay and on defence spending. They said Sunak was committed to staying the course and would serve in whatever way the party wished. 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. Boris Johnson used his column in the Daily Mail not to contemplate merging with Reform: “I say to my fellow Conservatives, we are the oldest, most successful political party in British history. We are capable of endless regeneration. We don’t need to try to absorb other parties, to try to acquire their vitality like a transfusion of monkey glands. “We need to occupy the space ourselves – and my humble suggestion to the 121 is that they need to rebuild that giant coalition of 2019, get back to some of the big themes that proved so successful that we won seats across the country.” Damian Green, a former leader of the Tory One Nation caucus who lost his Ashford seat to Labour, also warned on BBC Radio 4’s Today programme against “the idea that you somehow bring Nigel Farage in – that would be disastrous because you would lose millions of votes on the other side”. 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.