Britain’s former prime minister, Boris Johnson, abruptly resigned his parliamentary seat on Friday, another dramatic twist in the career of one of the country’s most flamboyant and divisive politicians.
Mr. Johnson has been under investigation from a committee of the House of Commons that was looking into whether he had lied to Parliament over lockdown-breaking parties in Downing Street during the Covid-19 pandemic.
On Friday, having received a confidential copy of their findings, he accused the committee of attempting to drive him out, adding: “They have still not produced a shred of evidence that I knowingly or recklessly misled the Commons.”
The committee had the power to recommend a sanction that could have led to Mr. Johnson being forced into an election to hold onto his constituency just outside London — a contest he might well have lost.
Instead, the former prime minister pre-empted that prospect by quitting. His decision means that there will now be a by-election in the constituency, but one he says he will not contest.
Mr. Johnson had made little secret of his ambition to win back the job of prime minister, and holding a seat in Parliament is a prerequisite of doing so. But it remained unclear whether this was a permanent departure from the House of Commons for Mr. Johnson, who once before resigned a seat to become London mayor, then returned to represent a different constituency.
Mr. Johnson was forced out as prime minister last July, but he has continued to cast a shadow over British politics in the last year, putting himself at the center of disputes over his handling of the pandemic and the accounts he gave to Parliament about the parties held at Downing Street during lockdown.
While the contents of the committee’s report were not clear, Mr. Johnson’s decision suggested that it would recommend more than a 10-day suspension, which could trigger an automatic election for his seat.
Appearing before the parliamentary committee in March, he acknowledged that he had made misleading statements in Parliament when he assured lawmakers that there was no breach of lockdown rules. He said he took full responsibility for the Downing Street gatherings. “That was wrong, I bitterly regret it,” he said at the time.
In a statement on Friday, Mr. Johnson went further. “I am not alone in thinking that a witch hunt is underway to take revenge for Brexit and ultimately to reverse the 2016 referendum result,” he wrote. “My removal is the necessary first step, and I believe there has been a concerted attempt to bring it about.”
The unexpected announcement could signal the end of a flamboyant career by a politician known for breaking rules and disregarding norms. But it could also be merely a twist in a career marked by frequent surges and setbacks.
“Politically, he hasn’t got that many friends,” Jonathan Powell, a former chief of staff to Prime Minister Tony Blair, said of Mr. Johnson. “He has a few die-hard supporters. But he doesn’t get a sympathy vote for his troubles, and he doesn’t have people behind him.”
Mr. Johnson left his options open in his statement by saying that he was “very sad to be leaving Parliament — at least for now,” while adding that he was “bewildered and appalled” at being forced out in a manner he characterized as anti-democratic.
Political analysts suggested that Mr. Johnson might be quitting in his constituency to run for a seat in a safer Conservative seat, like one vacated by Nadine Dorries, a loyalist of Mr. Johnson who announced Friday that she would not stand for re-election. He could also try to run in the more friendly constituency of Henley, which he represented once before.
But even while serving as an elected lawmaker, Mr. Johnson has been making large sums as a speaker at events around the globe. And he may have calculated that, for now at least, it was better for his reputation to leave Parliament on his terms rather than risk losing his constituency in a public vote.
The prospect of a by-election in Mr. Johnson’s seat of Uxbridge and South Ruislip may not be a welcome one for Prime Minister Rishi Sunak, whose Conservative Party trails the opposition Labour Party in opinion polls. Defeat there would be a blow to the party’s morale as it readies itself for a general election that must take place by January 2025 but which is expected in the second half of next year.
And Mr. Johnson’s angry resignation will reawaken memories of the extraordinary political infighting that afflicted the government last year when Britain saw two prime ministers toppled in quick succession.
Angela Rayner, deputy leader of the Labour Party, said Mr. Johnson was leaving “in disgrace,” adding: “The British public are sick to the back teeth of this never-ending Tory soap opera played out at their expense.”
For all of Mr. Johnson’s ability to command headlines, his popularity has waned since he left Downing Street. Mr. Sunak, who served as chancellor of the Exchequer under Mr. Johnson and succeeded him after the brief interlude of Liz Truss, has won credit for putting the Conservative-led government on more stable footing.
In his populist rise and litany of grievances as his fortunes have turned, Mr. Johnson’s saga resembles that of Donald J. Trump, who was indicted on Thursday for obstruction of justice in his handling of classified documents.
Mr. Johnson’s legal problems are arguably less consequential than those of Mr. Trump, who faces multiples felony indictments. But his political fortunes may be less promising, at least in the short run, given Mr. Trump’s healthy lead in the polls of Republican primary candidates.