The former chancellor's supporters said on Friday night he had received nominations from 100 Tory MPs to pass the threshold required way ahead of Monday's deadline. Boris Johnson was lagging behind, as was Commons Leader Penny Mordaunt who became the first to confirm her candidacy to replace Liz Truss as prime minister. But Johnson has told allies he is "up for it" and would fly back from his holiday in the Dominican Republic to enter the race and attempt an extraordinary comeback. There is speculation among backers of the old Downing Street neighbours that they could strike a deal to stand together, but this would need them both to bury a lot of rancour. Sunak, who came second against Truss in the last race six weeks ago, has around 82 public declarations, far ahead Johnson's 48, while Mordaunt struggles on 18. But a source in the former chancellor's camp told the PA news agency he had won the backing of 100 colleagues to make it to the next stage. Tory MPs will vote on Monday, and two candidates will be put forward to the Tory membership unless one pulls out, with a result being announced on Friday. Johnson was winning Cabinet support from ministers including Jacob Rees-Mogg, Simon Clarke and Alok Sharma. But former Tory leader William Hague warned Johnson's return would lead to a "death spiral" for the Conservative Party. "And I think it's possibly the worst idea I've heard of in the 46 years I've been a member of the Conservative Party," he told Times Radio. Neither Johnson or Sunak have officially launched their campaigns, unlike Mordaunt who put her name forward with a pledge to re-unite the bitterly divided Tory Party. "I've been encouraged by support from colleagues who want a fresh start, a united party and leadership in the national interest," Mordaunt said in a statement posted on social media. "I'm running to be the leader of the Conservative Party and your Prime Minister - to unite our country, deliver our pledges and win the next GE (general election)." Johnson's supporters have been urging him to mount a comeback six weeks after he left No 10 after being forced to resign by a Cabinet rebellion over a series of scandals. Ally James Duddridge said Johnson has told him he is "up for it", and will head back from his Caribbean holiday and land in the UK on Saturday. Some MPs have warned they would resign the Tory whip and sit in the Commons as independents if Johnson returns to Downing Street. Defence Secretary Ben Wallace ruled himself out as a candidate, saying he was "leaning towards" backing his long-time ally Johnson. Wallace praised his record on investing in defence and pointing to the "huge majority" he won in 2019. He told broadcasters: "This will be potentially our third prime minister since the general election of 2019 - that means we have to think about that legitimacy question that the public will be asking themselves, and also about who could win the next election - that's obviously important for any political party at the time." Sunak won the backing of Sajid Javid, his predecessor as chancellor who backed Truss in the last race and Johnson in 2019. Javid said Sunak has the "values our party needs" to help them "move on from the mistakes of the past". Former minister Johnny Mercer also backed Sunak, and argued he could not put himself or his constituents through another Johnson administration after the "terrible" lows last time around. "I love Boris to bits, and he's got amazing qualities for this country, but it is now time for serious, competent, straight-forward and values-based governance," he told BBC Radio 4.