LONDON — One of his lawmakers calls him a “dead man walking.” The leader of the Scottish Conservatives says he should quit. And, after a humiliating day for Prime Minister Boris Johnson in Parliament on Wednesday, some cabinet members were notably slow to voice support.
After admitting he attended a party in Downing Street during Britain’s first and fiercest coronavirus lockdown, Mr. Johnson is in big trouble, two years after leading his Conservatives to their biggest election victory in decades.
Here is a guide to just how much trouble, and what could happen next.
This is about much more than a few drinks in a garden.
On Wednesday, Mr. Johnson apologized for attending a gathering in May 2020 that apparently violated the lockdown rules he had imposed on England. The party was held in the garden of No. 10 Downing Street, where British prime ministers both live and work, and staff were asked to “bring your own booze.”
Mr. Johnson said he thought it was a work event, but that did little to mollify critics.
It’s the latest of a series of reports about parties in Downing Street while restrictions were in force, claims that have depressed the Conservatives’ opinion-poll ratings and led to the tearful resignation of an aide who was caught on video laughing about a Christmas “wine and cheese” gathering. A senior civil servant, Sue Gray, has been assigned to investigate reports of no fewer than seven parties that might have breached rules in 2020.
The most recent disclosure is the most serious for several reasons. After insisting for weeks that all rules were followed, Mr. Johnson has admitted being present at an event to which dozens of people appear to have been invited, at a time when the restrictions prohibited socializing with more than one other person, even outside, in almost all circumstances.
Some lawmakers responded to Mr. Johnson’s apology with testimony from people who were barred from visiting dying relatives.
Mr. Johnson’s lawmakers could simply force him out.
In Britain it is hard to get rid of a serving prime minister, but far from impossible. The nation’s top job goes to the leader of the political party with a Parliamentary majority. The party can oust its leader and choose another one, changing prime ministers without a general election.
Under the Conservative Party’s current rules, its members of Parliament can hold a binding vote of no confidence in Mr. Johnson if 54 of them write to formally request one. The request letters are confidential.
So far only four Conservatives in Parliament have publicly called on Mr. Johnson to quit. Only one senior lawmaker knows how many have written letters, and he would only make the number public if it reached the threshold for a challenge.
In a no-confidence vote, held by secret ballot, Mr. Johnson would keep his job by winning a simple majority of Conservative lawmakers. He would then be safe from another such challenge for a year unless the rules were changed.
His cabinet could fatally undermine him.
Cabinet rebellions destabilize prime ministers and can prove crucial in pushing them toward the exit. The catalyst for Margaret Thatcher’s demise in 1990 was the resignation of Geoffrey Howe, a disaffected former ally, and Theresa May lost several ministers — including Mr. Johnson himself, who quit as foreign secretary in 2018.
As prime minister, Mr. Johnson has more or less maintained cabinet discipline so far. But one senior minister, the former Brexit negotiator David Frost, quit late last year, citing policy differences. And it took several hours for Rishi Sunak, the chancellor of the Exchequer, to express lukewarm support for Mr. Johnson after his apology. Of course it might just be a coincidence, but Mr. Sunak is a leading contender to take over if Mr. Johnson falls.
Or he could succumb to quiet pressure.
Once this was known as a visit from the “men in gray suits,” a phrase dating from an age when all key power brokers were men. In those days, when a group known as the “magic circle” chose the Conservative Party leader, such bigwigs could withdraw support, too, and ask the prime minister to resign. Nowadays things aren’t quite like that, but leaders can still be persuaded to depart on your own terms and keep a measure of dignity, or risk being booted out unceremoniously.
Mrs. May resigned in 2019, a few months after surviving a leadership challenge vote, when it was clear that her support within the party had ebbed so much that her position was hopeless. Similar pressure, accompanied by ministerial resignations, was used to evict Tony Blair, the Labour Party prime minister, from Downing Street in 2007.
The fatal blow, if it comes, may be months away.
Timing a coup is never easy. Critics are unlikely to force a confidence vote until they think Mr. Johnson is so damaged that he could lose. That tipping point may be near but, critically, there is no consensus on who would replace Mr. Johnson and therefore no single cabal orchestrating a challenge.
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Mr. Sunak is the front-runner and Liz Truss, the foreign secretary, is a leading contender, but several others would be likely to run. They all need to be careful. In the past, ambitious rivals have suffered from being seen as disloyal to the prime minister and failed to win the crown (though not Mr. Johnson, who opposed Mrs. May and then succeeded her).
For most Conservative lawmakers the question is whether a change would help them. None of his potential successors have shown they can match the appeal he demonstrated in leading the party to a landslide victory in 2019.
Most Conservative lawmakers seem to be waiting for Ms. Gray’s internal inquiry before deciding which way to jump. Despite her reputation for independence, she is in a rare and awkward position — an unelected civil servant compiling a report that could prove terminal for her elected boss. So some analysts expect her to restrict her findings to facts she establishes without making a direct judgment on Mr. Johnson’s conduct.
Mr. Johnson has bounced back before.
Escaping scrapes is one of the prime minister’s defining skills. A Conservative former prime minister, David Cameron, once described Mr. Johnson as the “greased piglet” of politics: His career has contained no shortage of dismissals and humiliations, each so far followed by a greater triumph.
To slip out of this tight corner, Mr. Johnson needs to avert cabinet resignations and prevent a rush of letters demanding a no-confidence vote. He will then hope that Ms. Gray’s report is diplomatic enough for him to survive, albeit after another apology and a purge of his top team. He could please his party’s lawmakers by ending all coronavirus restrictions later this month, giving him more breathing space.
But he might have even more trouble ahead.
Aside from the crisis over Downing Street parties, things look sticky for the government. Energy bills are soaring, inflation is spiking and interest rates have risen at a time when Mr. Johnson is just about to raise taxes. The opposition Labour Party has gained traction with its complaints about a “cost of living squeeze.”
Mr. Johnson’s enemies are circling and Mr. Sunak and Ms. Truss are maneuvering. In May the Conservatives face local elections which will test Mr. Johnson’s popularity. Opinion polls show a collapse of support for him personally and suggests that he is now dragging his party down. One recent survey put the Conservatives 10 points behind Labour, its worst showing in eight years.
Mr. Johnson became prime minister in 2019 because his party correctly judged that he would win them a general election. If it concludes that he will lose them the next one, his days are numbered.