LONDON — A day after suffering a crushing rebuke from his country’s highest court, a notably unchastened Prime Minister Boris Johnson appeared before a hastily reconvened Parliament and doubled down on his hard-line Brexit approach.
If anyone had expected Mr. Johnson to appear before the lawmakers hat in hand after being forced to cut short a trip to the United Nations and return back home, they were presumably disappointed.
“Come on!” Mr. Johnson yelled over a barrage of jeers as he urged his opponents to stage a vote of no confidence in him.
“Humbug,” he declared, when one Labour lawmaker, Paula Sherriff, made an emotional plea for him to stop using inflammatory language.
Mr. Johnson was not meant to be in Parliament on Wednesday. Neither were M.P.s.
But a day earlier, the British Supreme Court ruled that the prime minister had acted unlawfully in orchestrating the suspension of Parliament as he made a final drive to withdraw Britain from the European Union, “do or die.”
With that, lawmakers who had been told to hit the road for five weeks found themselves unexpectedly back in their seats. They promptly set about waving the prime minister’s legal defeat in his face.
Amid a scene of tumult, Jeremy Corbyn, the leader of the opposition Labour Party, called on Mr. Johnson to resign, describing him as a “dangerous prime minister who thinks he is above the law” and unfit for office.
“For the good of the country he should go,” Mr. Corbyn said.
Mr. Johnson and his colleagues were unmoved, even in the face of a unanimous ruling against them by the court.
“It is absolutely no disrespect to the judiciary to say I think the court was wrong to pronounce on what is essentially a political question at a time of great national controversy,” the prime minister told lawmakers. The issue of whether Parliament could be sent away, he argued, was not one for the courts.
Mr. Johnson went on to goad his opponents, accusing them of “sheer selfishness and political cowardice,” for refusing to agree to a general election, and challenging them to try to force him out.
He also infuriated some lawmakers when he said that the best way of bringing the country together and of honoring the memory of Jo Cox — a Labour lawmaker who was murdered in 2016 — was to get Brexit done. Ms. Cox was an opponent of Brexit.
Mr. Johnson’s bombastic appearance did little to dispel the impression that he wants to present himself to voters as the champion of the people against a Parliament that is blocking the Brexit that Britons voted for in a 2016 referendum.
But for the moment, Parliament is not giving him his election.
Instead, the opposition is trying to subject Mr. Johnson to a form of slow political torture, seeking to weaken him and to force him to break his promise to leave the European Union by Oct. 31, even if he cannot reach a formal agreement with Brussels on the terms of departure.
An election, Mr. Corbyn said, can take place as soon as Mr. Johnson secures another delay to withdrawal, avoiding the possibility of a “no deal” Brexit.
Mr. Corbyn also took the opportunity to bring up new conflict-of-interest allegations against the beleaguered prime minister over public funding given, when he was mayor of London, to an American entrepreneur and close friend, Jennifer Arcuri.
The mood was stormy on another remarkable day in the Brexit saga.
Mr. Johnson has promised to extract Britain from the European Union by the end of next month, even if it means an economically risky exit without any agreement.
But opposition lawmakers think they have him in a trap. A law passed earlier this month would force Mr. Johnson to seek a third Brexit delay if he cannot strike a new exit deal that Parliament can ratify.
Mr. Johnson insisted on Wednesday that he was pursuing an agreement, but the highly charged atmosphere at Westminster probably makes it less likely that any new Brexit deal could get through Parliament, even if one can be negotiated with the European Union.
Though there is speculation that Mr. Johnson might try to find a legal loophole to prevent him having to apply for a Brexit extension, no obvious one has emerged so far.
Geoffrey Cox, the attorney general, has said the government will comply with the law. But at the House of Commons on Wednesday, Mr. Cox also declared that, in failing to agree on any Brexit path, Parliament was a “disgrace.”
“It is a dead Parliament,” he said. “It has no moral right to sit on these green benches.” He dismissed lawmakers as “too cowardly” to set a general election.
That provoked a furious response from one Labour lawmaker, Barry Sheerman, who said the government had tried to shut down Parliament so that it “couldn’t work as a democratic assembly.”
Shouting and pointing across the chamber at Mr. Cox and the Conservative benches, he said, “For a man like him, a party like this, a leader like this, this prime minister, to talk about morals and morality is a disgrace.”
Beyond angry lawmakers, Mr. Johnson faces some logistical problems.
Unless lawmakers agree to a short suspension of Parliament, his Conservative Party conference, scheduled for Sunday in Manchester, might have to be reorganized, and even curtailed, because lawmakers will be needed in London.
The government was also planning to open a new session of Parliament next month, to showcase its policy agenda.
But that would require Mr. Johnson to ask Queen Elizabeth II to suspend Parliamentary sittings. Again.
This suspension would be brief, given that its last attempt to do so landed Mr. Johnson in such hot water, the government will have to be careful how it proceeds with any new request.