Boris Johnson and his former Finance Minister Rishi Sunak appeared Friday to be the lead runners to replace outgoing British Prime Minister Liz Truss.

After Truss quit on Thursday, ending her six weeks in power, those who want to replace her were trying to find the 100 votes from Conservative lawmakers needed to run in a contest that the party hopes will reset its ailing fortunes.

With the Conservatives all but facing a wipeout in the next national election, according to opinion polls, the race is on to become the fifth British premier in six years.

The winner will be announced on either Monday or Friday next week.

In what would be an extraordinary comeback, Johnson, who was ousted by lawmakers just over three months ago, was running high up the ranks alongside Sunak to be crowned the next prime minister.

"I think he's got that proven track record to turn around things. He can turn it around again. And I'm sure my colleagues hear that message loud and clear," Conservative lawmaker Paul Bristow said of Johnson on LBC radio.

"Boris Johnson can win the next general election," he said.

Johnson, who left office comparing himself to a Roman dictator brought into power twice to fend off crises, might face difficulty in reaching the 100 votes after his three-year tenure was blighted by scandals and allegations of misconduct.

One of his former advisers, who no longer speaks to Johnson and requested not to be identified, said he was unlikely to reach the target, having alienated dozens of Conservatives during his scandal-ridden tenure.

The Financial Times newspaper, which called for a new election, said a Boris comeback would be "farcical."

Will Walden, who also previously worked for Johnson, said the former prime minister was returning from holiday and was taking soundings.

"The country needs a grown-up, serious leader. Boris had his chance, let's move on. I suspect that is not what the Tory party will do, they may well re-elect him," he told the BBC.

Business minister Jacob Rees-Mogg said he was backing Boris, tweeting his support with the hashtag "#Borisorbust."

British Defence minister Ben Wallace also joined Rees-Mogg Friday and said he would not stand in the contest to replace Liz Truss as prime minister and was leaning towards backing former leader Johnson.

The contest began on Thursday, hours after Truss stood in front of her Downing Street office to say she could not go on.

Sunak, the former Goldman Sachs analyst who became finance minister just as the COVID-19 pandemic arrived in Europe and was runner-up to Truss in the previous leadership contest this summer, is the bookmakers' favorite, followed by Johnson.

Running in third is Penny Mordaunt, a former defense minister popular with party members. None have formally declared their candidacy.