LONDON - Boris Johnson is flying back to Britain as he considers an audacious attempt to win a second term as prime minister only weeks after he was forced to step down, with some colleagues warning his comeback could create more political chaos.

The potential candidates to replace Prime Minister Liz Truss, who dramatically quit on Thursday after only six weeks in power, were embarking on a frantic weekend of lobbying to secure enough nominations to enter the leadership contest before Monday's deadline.

Johnson, who has on holiday in the Caribbean when Truss resigned and has said nothing publicly about a bid for his old job, has received the support of dozens of Conservative lawmakers but needs to secure 100 nominations to be considered.

The trade minister James Duddridge said on Friday Johnson told him he is "up for it" and the former leader will fly back to Britain on Saturday.

Johnson was booed by some passengers on the plane to Britain, according to a Sky News journalist on the flight.

It would be an extraordinary political resurrection for the former journalist, who left office shrouded in scandal but grumbling that his colleagues "changed the rules halfway through" a race - a swipe at the Conservative lawmakers who did not allow him to serve a full term.

Former defence minister Penny Mordaunt became the first candidate to officially declare an intention to run to be the next leader of the Conservative Party, but Johnson and Rishi Sunak, once his finance minister, led potential contenders ahead of voting next week.

The prospect of the return of Johnson to government is a polarising issue for many in the Conservative Party, which is deeply divided after seeing off four prime ministers in six years.

For some Conservative lawmakers, Johnson is a vote winner, able to appeal across the country not only with his celebrity but also with his brand of energetic optimism.

For others Johnson is a toxic figure and the question is whether he can convince the dozens of lawmakers who abandoned him that he is now the person who can unite the party and turn around its flagging fortunes.

"DEATH SPIRAL"

The former Conservative leader William Hague said on Friday Johnson's return was possibly the worst idea he had heard in almost half a century as a party member. He said it would lead to a "death spiral" for the Conservatives.

If Johnson can secure the required number of nominations, he is likely to go head-to-head with Sunak, who quit as his finance minister in July, claiming that his former boss was unable to take tough decisions.

Sunak is the first leadership candidate to hit the threshold of 100 nominations to enter the contest before Monday's deadline, according to media reports. Johnson currently has about half that support.

Johnson is currently under investigation by parliament's Privileges Committee to establish whether he lied to the House of Commons over lockdown-breaking parties. If ministers are found to have knowingly misled parliament, they are expected to resign.

The contest to become Britain's fourth prime minister in four years has been accelerated to take only a week. Under the rules, only three candidates will be able to reach the first ballot of lawmakers on Monday afternoon, with the final two put to a vote of party members for a result by next Friday.

(Reporting by Andrew MacAskill; Editing by Toby Chopra)