A FORMER chief Tory Brexiteer has warned Boris Johnson taking on a second term as prime minister would be a “guaranteed disaster”.

Mr Johnson is scrambling for enough Tory MPs to support his bid to make a dramatic return for a second spell as prime minister following the resignation of Liz Truss.

He needs the backing of 100 Conservative MPs, with Rishi Sunak and Penny Mordaunt already officially declared as candidates.

Yesterday, Sir James Duddridge, a friend of Mr Johnson, said the former prime minister had the support of the 100 MPs required to reserve his place in the vote.

But Sunak supporter Richard Holden cast doubt on this suggestion, arguing that the equivalent number of public declarations had not been made “because they don’t exist”.

Mr Johnson is to face an inquiry into whether he lied to the Commons over the partygate scandal, for which he was fined by police.

If found guilty by the Commons Privileges Committee, he could face recall proceedings that would leave him battling for his seat in the Commons if he receives a suspension of 10 days or more.

Steve Baker, the current Northern Ireland minister, has suggested Mr Johnson would be better suited as “chairman” of the Tory party.

Mr Baker, the former head of backbench Brexiteers, told Sky’s Sophy Ridge On Sunday: “I think it would be for the best if Boris did something big and statesmanlike.

“I mean If he wants to come back as prime minister, he would need to do it after this privileges issue is settled.

“I think he’d make an amazing chairman of the party… “But what we can’t do is have him as prime minister in circumstances where he’s bound to implode, taking down the whole government within and we just can’t do that again.”

He added: “I’m afraid the trouble is because of the (Commons Privileges Committee) vote, Boris would be a guaranteed disaster.

“There’s going to be a vote before the House of Commons on this issue of privileges, whether he will deliberately misled the house.

“In that vote it’s guaranteed there’ll be a large number of Conservatives who will refuse, as they see it, to lay down their integrity to save him, and at that moment his premiership will collapse.”

He added: “It’s a guaranteed nailed-on failure and we cannot allow it to happen.”

Despite Mr Johnson so far failing to garner enough support from Tory MPs, one of his key allies has suggested he will run to return as prime minister.

Business and Energy Secretary Jacob Rees-Mogg, a staunch ally of Mr Johnson, told the BBC’s Sunday With Laura Kuenssberg programme: “I have been speaking to Boris Johnson, and clearly he’s going to stand, there’s a great deal of support for him”.

Conservative former cabinet minister Dominic Raab also warned that the partygate probe would overshadow a Mr Johnson premiership.

He told BBC One’s Sunday With Laura Kuenssberg programme: “In a matter of days, not weeks, he’s going to see televised witness testimony, including his own, which is going to take him right back into that spiral.”

But Mr Johnson won the support of Nadhim Zahawi, the Chancellor of the Duchy of Lancaster, who said the ex-Prime Minister “got the big calls right” and argued “Britain needs him back”.

He tweeted: “When I was chancellor, I saw a preview of what Boris 2.0 would look like.

"He was contrite and honest about his mistakes. He’d learned from those mistakes how he could run No 10 and the country better.”

Mr Zahawi, who joined other Cabinet ministers including Ben Wallace, Anne-Marie Trevelyan and Jacob Rees-Mogg in backing their former boss, urged him to resign as prime minister in July.

Labour’s shadow communities secretary Lisa Nandy told Ridge: “It’s extraordinary watching Tory MPs who put in letter of no confidence in him just a few weeks ago saying he wasn’t fit to hold the highest office now talking openly about trying to bring him back.

"It is a sign of absolute utter desperation in the Tory party.”