LONDON — His support crumbling, his government in disarray, his alibis exhausted, Prime Minister Boris Johnson of Britain tried frantically on Wednesday to salvage his position, even as a delegation of cabinet colleagues traveled to Downing Street to plead with their scandal-scarred leader to step down.
More than 30 government ministers or aides quit, multiple Conservative Party lawmakers urged Mr. Johnson to resign, and he got a withering reception in Parliament, where backbenchers jeered, “Bye, Boris!” as he left by a side door after a merciless grilling over his handling of the party’s latest sex-and-bullying scandal.
On a day of fast-moving developments, Mr. Johnson vowed to fight on, insisting he had a mandate from voters to steer Britain into its post-Brexit future, even as rebellious cabinet ministers tried to dislodge him.
On Wednesday evening, Mr. Johnson fired one of his closest advisers, Michael Gove, from a powerful economic post in the Cabinet. Earlier in the day, the BBC reported that Mr. Gove had urged Mr. Johnson to resign.
That moment of drama was followed by the late-night resignation of another cabinet minister, Simon Hart, the Welsh secretary.
Elsewhere in Westminster, lawmakers considered — and then postponed, for a few days at least — a change in party rules that would allow another confidence vote, possibly next week, against the prime minister, who survived such a vote just a month ago.
There was a growing consensus that, however events play out over the next few hours or days, the curtain was falling on the era of Boris Johnson. Less than three years after he entered Downing Street, before riding a wave of pro-Brexit passion to win a landslide election victory, Mr. Johnson seemed cornered — a protean political gambler finally out of moves.
That does not mean the end will come quickly or gracefully. Mr. Johnson resisted the appeals of the cabinet delegation to resign. He has not ruled out calling a snap election to throw his fate to British voters. Such a move would need the assent of Queen Elizabeth II, which could precipitate a political crisis.
“The job of a prime minister in difficult circumstances, when he’s been handed a colossal mandate, is to keep going,” a grim-face Mr. Johnson declared in Parliament, rejecting yet another call for his resignation.
The opposition leader, Keir Starmer, brushed that off, excoriating Mr. Johnson and the cabinet ministers who have yet to abandon the prime minister after a seemingly endless stream of scandals. The latest chapter of this drama kicked off on Tuesday with the resignations of two senior ministers.
“Anyone quitting now, after defending all that, hasn’t got a shred of integrity,” said Mr. Starmer, the Labour Party leader, staring balefully across a table at Mr. Johnson. “Isn’t this the first recorded case of the sinking ship fleeing the rats?”
For all the drama in Parliament, the real action on Wednesday occurred out of sight, where Mr. Johnson’s dwindling band of supporters and growing gang of adversaries maneuvered. Mr. Johnson’s dismissal of Mr. Gove was particularly charged, since in 2016, Mr. Gove had derailed Mr. Johnson’s first bid for the Tory Party leadership by unexpectedly entering the contest himself.
The latest chapter in the crisis began on Tuesday when two senior cabinet ministers abruptly resigned: the chancellor of the Exchequer, Rishi Sunak, and the health secretary, Sajid Javid. The trigger was Mr. Johnson’s handling of a case involving Chris Pincher, a Conservative lawmaker who admitted having been drunk at a private members’ club in London where, it was alleged, he groped two men.
Given the speed with which Mr. Johnson’s government was unraveling, many Tory lawmakers believe that Mr. Johnson needs to be replaced quickly to mitigate the electoral damage to the party. Even before the latest scandal broke, opinion polls showed the Conservatives trailing well behind Labour.
The dilemma for the party’s senior figures was whether to permit a swift no confidence vote against Mr. Johnson. Under existing party rules, there cannot be another such vote until a year after the last one — next June.
But the leaders of the 1922 Committee, which represents backbench Conservative lawmakers, have been willing to rip up their rule book before: When Mr. Johnson’s predecessor, Theresa May, won a confidence vote in 2018 but then failed to push her Brexit plan through a log-jammed Parliament.
According to Graham Brady, who chairs the committee, the proposed rule change was in his pocket when he went to meet the prime minister, but he never showed it to Mrs. May, who agreed to step aside.
Under a fast-track scenario this time, lawmakers would hold the confidence vote before the summer recess. If Mr. Johnson lost, they would move fast to select two leading candidates to replace him as party leader and prime minister. The two contenders would then run in a final contest where the selection is by the party’s members.
Tobias Ellwood, a former minister and critic of Mr. Johnson, said he had reservations about changing the rules but believed it would happen if the prime minister refused to leave on his own. He likened a change of leader to a trip to the dentist.
“We have been putting it off,” he said. “You’ve got to go to the dentist and get through it — getting rid of Boris is that trip to the dentist.”
Moving fast, Mr. Ellwood said, would allow the party to use the summer vacation to conduct the leadership election and give a new prime minister a platform at the Conservative Party’s annual conference in the fall. That looked increasingly likely as the situation worsened for Mr. Johnson on Wednesday, with more than 30 junior ministers and ministerial aides submitting their resignations.
At one point, five junior ministers quit in the same resignation letter, including the equalities and local government minister, Kemi Badenoch, and Neil O’Brien, a minister with responsibility for Mr. Johnson’s policy of “leveling up” prosperity across the country.
Downing Street was unable to give a timetable for replacing others who declared they were no longer able to serve Mr. Johnson, including the Treasury minister, John Glen, and his Home Office colleague, Victoria Atkins.
Mr. Johnson had moved quickly to announce replacements for Mr. Sunak and Mr. Javid, signaling that he planned to try to steady the government. And he did his best to project a defiant image.
Confronted by the prospect of a new confidence vote, Mr. Johnson might opt to call a general election instead, even if the prospects for his party are bleak. The prime minister has reminded critics repeatedly of his party’s landslide victory in 2019, when he vowed to “Get Brexit Done,” and thrashed a divided Labour Party.
Constitutional experts argue that the queen might refuse to grant an election on the grounds that the Conservatives still have a sizable parliamentary majority. However, rejecting such a request might be difficult for Buckingham Palace, which prides itself on staying above politics. Moreover, the Labour Party is eager for an election and would relish a fight against a discredited prime minister.
Above all, however, there are Mr. Johnson’s Houdini-like instincts. In the last three years, he has survived multiple investigations, a criminal fine by the police, and a no-confidence vote among Conservative lawmakers. He may believe he can escape yet again.
“Unlike most leaders, he doesn’t care how much damage he does on his way out the door,” said Jonathan Powell, who served as chief of staff to a former prime minister, Tony Blair. “There isn’t anyone in our history who’s had this kind of nature. Our system is not built for something like this.”