LONDON — For Britain’s bare-knuckled new prime minister, Monday marked the end of what is surely one of the most abysmal starts any British leader has ever endured.
As a new law went into effect blocking a “no deal” Brexit, lawmakers also prepared to hand Prime Minister Boris Johnson yet another defeat — rebuffing his bid for a snap election.
By Monday’s end, it had become clear that if Mr. Johnson had thought he could outfox Parliament by suspending it, sidelining lawmakers at a critical moment in the Brexit debate, he was the one who had been outmaneuvered.
Now, the man who promised to deliver Britain’s withdrawal from the European Union “do or die,” formal withdrawal agreement or not, is suddenly flailing for a new strategy, more than three years after Britain voted to leave the European Union in a referendum.
Even the day’s only silver lining for Mr. Johnson came with a poison pill.
John Bercow, the speaker of the House of Commons — and a thorn in the side of the government throughout the Brexit debate — announced his plans to step down. But he timed it so that the current Parliament, which is packed with opponents of the prime minister, would choose his successor.
“Johnson is a toothless prime minister who desperately needs a snap election to give some credibility to his Brexit strategy,” wrote Kallum Pickering, a senior economist with Berenberg Bank. But, he said: “For the opposition parties, it makes little sense to give Johnson the election on his terms. That would return the initiative to him.”
The motion to suspend Parliament on Monday, or “prorogue” it, and send lawmakers away for five weeks came after eight days of head-snapping moves and countermoves in Parliament.
The suspension, announced in principle less than two weeks ago, was denounced by critics as a transparent, anti-democratic effort to sideline Parliament while the government forced through a no-deal Brexit.
But the government’s move to suspend Parliament backfired, serving to unite the disparate opposition, incite a revolt within Mr. Johnson’s own party and produce the bill that now blocks a no-deal Brexit. On Monday, that bill became law when it completed the final stage of passage, a formality known as royal assent.
The turbulent week has left Mr. Johnson in a tight corner. He has promised to leave the bloc on Oct. 31 — without an agreement if necessary — and said last week that he would rather be “dead in a ditch” than request another delay to a process that has already been put off twice.
Digging his way out of that promise could be tough, because a majority of lawmakers think that a no-deal Brexit would be disastrous. The new law is intended to force Mr. Johnson to request another extension if he cannot secure a withdrawal agreement with European Union officials before the Oct. 31 deadline.
As recently as a few weeks ago, Mr. Johnson said the chances of leaving the European Union without a deal were a million to one against; he now puts the prospects as “touch and go.”
But many of his critics believe the prime minister’s real agenda is political. They believe he plans to fight for re-election as the candidate for Brexit at any cost, rallying right-wing voters behind him and crushing the threat from the hard-line Brexit Party, led by Nigel Farage.
From Mr. Johnson’s perspective, the suspension of Parliament at least provides some relief by removing the possibility of further embarrassments and defeats at the hands of lawmakers after a week of tumultuous setbacks.
But it also means that prospects of a general election before the Oct. 31 Brexit deadline have slipped away.
Mr. Jonson had hoped to use a big win in an election before that date to empower his government to push through withdrawal from the European Union, with or without a deal. Lawmakers, however, need to approve an early election, and with the suspension of Parliament lawmakers cannot do so for at least five weeks. It would then take several weeks to organize an election.
With so much riding on an election that most expect toward the end of the year, the rival parties are trying to ensure that the timing best suits them.
Mr. Johnson’s opponents rejected his call for a vote in October because they believe that their interests would be better served by a vote that comes after the deadline for withdrawal, at least if Mr. Johnson fails in his categorical pledge to deliver Brexit by Oct. 31.
They also know that there is a mood of discontent inside the ruling Conservative Party because Mr. Johnson last week expelled 21 lawmakers from his party — including some of its best-known figures — when they rebelled and supported legislation to prevent a no-deal Brexit.
Since then, Mr. Johnson has suffered the resignation from the government both of his brother, Jo Johnson, and of Amber Rudd, the high-profile former work and pensions secretary who quit over the weekend partly in protest of the party cull, and of Mr. Johnson’s broader Brexit strategy.
As the last hours of the parliamentary session ticked down on Monday night, Mr. Johnson had still yet to win a vote as prime minister.
Lawmakers voted against the government to demand the release of private messages sent by close advisers to Mr. Johnson about the decision to suspend Parliament, and of documents about the possible impact of a leaving the European Union without a deal.
Then Mr. Johnson was defeated on a motion brought by the Labour leader, Jeremy Corbyn, reaffirming the obligation of government ministers to uphold the rule of law. Mr. Johnson allowed the motion to pass without opposition.
Mr. Corbyn introduced the motion in light of reports in recent days that Mr. Johnson was planning to flout the law blocking a no-deal Brexit by refusing to ask Brussels to delay the current deadline of Oct. 31. Mr. Corbyn called that an “assault on the rule of law.”
Ministers insist the prime minister will not break the law, but still suggest the government is looking for loopholes to avoid Mr. Johnson having to ask Brussels for an extension. They did not explain how that circle can be squared.
One possibility is that Mr. Johnson may strike a new deal with the European Union, but the odds against that are long.
A meeting Monday with the Irish prime minister, Leo Varadkar, in Dublin, yielded nothing new on the biggest sticking point, the so-called Irish backstop plan to keep open the border between Ireland and Northern Ireland, which is part of the United Kingdom.
Mr. Johnson could try to circumvent the new law, perhaps by sabotaging the prospects of a Brexit extension from the European Union by making it clear that he will be an obstructive force in Brussels.
But anything too blatant might land him in court, so another course of action might be to call a vote of confidence in his own government, or simply to resign and leave another politician to request the delay, gambling that an election would follow soon.
Relinquishing power might, however, be a tough call for a politician who has spent so much time and energy, and provoked such much turmoil, in his successful bid to reach the top job in British politics.