Could Boris Johnson really make a comeback?

Boris Johnson, the man ousted as UK prime minister by his own government just three months ago, has emerged as an early front-runner to be the next prime minister.

His replacement Liz Truss crashed and burned after 45 days in the job, announcing her resignation after being forced to ditch most of her policy programme after it spooked the financial markets.

A second Johnson premiership would be an extraordinary turnaround even for a politician who has made miraculous comebacks before.

No one has returned as prime minister after resigning as leader since William Gladstone 140 years ago.

Mr Johnson won a landslide election victory in 2019 - but was forced out by his own MPs after three years in office, following a string of scandals. Under the British constitution, the ruling party can change leaders between general elections.

His final months in office were dogged by accusations he broke ministerial rules by not telling the truth about Covid lockdown-busting parties in Downing Street.

He remains under investigation by the Parliamentary Standards Committee, which in theory could lead to him being suspended from Parliament, or even being kicked out as an MP.

The committee could hold televised evidence sessions in the coming weeks - even calling Mr Johnson to respond in person. Mr Johnson's supporters have dismissed the committee's investigation as a "witch hunt".

The prospect of Johnson's return to Downing Street has been met with horror by some Conservatives. Former leader Lord Hague warned it could lead to a "death spiral" for the Conservative Party.

Foreign Office Minister Jesse Norman said Mr Johnson returning as prime minister would be an "absolutely catastrophic decision" while Tory MP Sir Roger Gale has said he would quit the party.

But Mr Johnson's supporters, including cabinet members Jacob Rees-Mogg and Anne-Marie Trevelyan, and former home secretary Priti Patel, say he is the only contender with the backing of the voting public after winning the 2019 general election. They believe he can win the next election for the party too, despite the Labour Party's current commanding poll leads.

Mr Johnson has yet to officially announce he will stand. The first contender to break cover was cabinet minister Penny Mordaunt, who came third in the last leadership election and announced on Friday that she was standing. Former chancellor Rishi Sunak confirmed on Sunday that he would be throwing his hat into the ring.

In his final appearance at Prime Minister's Questions in July this year, Mr Johnson made it clear that he was planning a comeback.

He signed off with "hasta la vista, baby". He could only have dropped a heavier hint that he was not finished yet if he had used another catchphrase from the Terminator films: "I'll be back."

Leadership hopefuls need the backing of at least 100 Tory MPs by Monday afternoon to stay in the race.

This is no small task for a man who had 148 of his colleagues vote against him in a confidence vote in June - followed by nearly 60 ministerial resignations one month later.

The deluge of resignations followed revelations that Mr Johnson had ignored accusations of sexual misconduct against Chris Pincher before appointing him deputy chief whip.

On 5 July, two senior cabinet ministers resigned within minutes of each other - including then chancellor Rishi Sunak, who left claiming Mr Johnson was not competent or serious.

But before the resignations, pressure had been building on Mr Johnson for criticism over his handling of parties that took place in Downing Street during Covid lockdowns.

Mr Johnson was one of 83 people fined by police for a string of illegal parties - including a birthday party for Mr Johnson.

Labour leader Sir Keir Starmer said the former prime minister was "unfit for office". Scotland's Frist Minister Nicola Sturgeon called a Mr Johnson return a "ludicrous suggestion".

He was described as "Britain's Berlusconi" by the Liberal Democrats.

According to betting website Oddschecker, Rishi Sunak is the favourite to become the next prime minister. Mr Sunak has odds of 1/6 to take over from Liz Truss while Mr Johnson is 4/1 with Ms Morduant at 25/1.

If only a single candidate emerges the contest will be over on Monday - if not the new leader will be chosen by a vote from party membership on Friday 28 October.

Polls taken in the final days of Liz Truss' premiership have consistently shown Mr Johnson as the most popular successor among Tory members.

Patrick English, associate director of polling company YouGov, said "if Mr Johnson goes to the final two, he's got the edge".