Boris Johnson’s resignation has triggered fevered speculation about who might take over in Downing Street, with early momentum among MPs swinging towards Rishi Sunak, and Ben Wallace emerging as a favourite among Conservative party members. As a huge number of candidates weigh up whether to make a challenge, current and former cabinet ministers known to be drumming up support include Suella Braverman, Jeremy Hunt, Sajid Javid, Penny Mordaunt, Liz Truss and Nadhim Zahawi. Grant Shapps is also considering putting himself forward. But Michael Gove and Dominic Raab have ruled themselves out of the running, along with prominent backbencher Tobias Ellwood. A survey by JL Partners, a polling company, suggests Sunak, the chancellor who quit Johnson’s government this week, is in the lead with the public out of the main candidates, and the only one to be slightly ahead of Labour’s Keir Starmer when put to a head-to-head question. It shows him with a one-point lead over Starmer when asked who would make the best prime minister, and ahead of all his main rivals when asked the straight question of who should be leader. Javid is in second place. The poll of 2,000 people was conducted on Wednesday and Thursday. Sunak’s popularity plummeted with Conservative members after the furore over his wife’s non-dom tax status, but he has recovered some of his standing after he was one of the first two cabinet ministers to quit, alongside Javid. One Tory MP said they suspected he would want to launch a campaign with a lot of big name MPs and a slick operation but only if they thought he had enough support. Another MP from the party’s One Nation grouping said they supported Sunak, a Eurosceptic and rightwinger, “purely on the basis that he is clearly the most competent”. Wallace, the defence secretary, has not revealed whether he is interested in standing and does not appear to have a well advanced campaign. But he became a bookmakers’ favourite based on polling of party members by ConservativeHome. He refused to rule himself out of running for prime minister on a trip in the north of England on Thursday. Speaking in the morning, before Johnson confirmed he had resigned in Downing Street, Wallace told reporters “let’s see what the prime minister says” when asked if he would seek the top job. Truss, who cut short a trip to Indonesia to return to the turmoil at home, said on Thursday: “We need calmness and unity now and to keep governing while a new leader is found.” One of her backers, Alec Shelbrooke, told GB News he was supporting her on the grounds that “she’s got huge amounts of experience, she’s really leading the world on the foreign stage where our country is at the forefront of so many important international issues”. However, one Tory figure said Braverman, a leading Eurosceptic, was hoovering up many of Truss’s potential supporters while she was out of the country. Braverman, the attorney general, is also on the Eurosceptic right of the party and was also quick to reveal her intention to stand, before Johnson had even resigned. She told ITV’s Peston she wanted to shrink the size of the state and get rid of “woke rubbish”. Neither Kwasi Kwarteng, the business secretary, nor Priti Patel, the home secretary, have signalled their intentions yet but may not have enough wide support for a run. Quick out of the blocks to signal an interest were backbenchers Steve Baker and Tom Tugendhat, from opposite wings of the party. Tugendhat, on the One Nation side and chair of the foreign affairs committee, has previously said he would throw his hat into the ring. On Thursday, he said the party needed a “clean start” and three of his backers publicly declared their support, including One Nation group leader, Damian Green, the former first secretary of state. Meanwhile, Baker, a leading Eurosceptic and former Brexit minister, said he was mulling a leadership run after being urged by colleagues and looking at his recent appearances in the ConservativeHome list of members’ favoured candidates. He told Times Radio people are asking him to do it, and it would be “dismissive and disrespectful” if he did not heed expressions of support, though he said he regards the prospect with “something akin to dread”. A source close to Jake Berry, the leader of the Northern Research Group of MPs, told PoliticsHome he was considering a run. The source said: “He appeals to people because he gets what matters. He is the only well-known member of the party who has actually offered policies.”