Updated at 12:35 p.m. ET
British Prime Minister Theresa May has postponed a critical vote on the draft Brexit deal she negotiated with the European Union, conceding that it would not have enough support to pass Parliament if the vote were held Tuesday as scheduled.
"I've listened very carefully to what has been said in this chamber and out of it, by members from all sides," May told the House of Commons on Monday, only to be interrupted by a peal of derisive laughter from lawmakers.
"From listening to those views," she continued after the noise in the chamber ebbed, "it is clear that while there is broad support for many of the key aspects of the deal, on one issue — the Northern Ireland backstop — there remains widespread and deep concern. As a result, if we held the vote tomorrow, the deal would be rejected by a significant margin."
May did not immediately set a new date for the vote. She faces some looming deadlines, however. The prime minister must submit a final deal for parliamentary approval by Jan. 21, and the U.K. is set to leave the EU — regardless of whether a deal is in hand — on March 29.
That marks two years from the moment May invoked Article 50 of the treaty that established the European Union, declaring the U.K.'s intention to become the first member to leave the international bloc. The declaration of intent set the formal gears of Brexit in motion — and at the time, appeared to be a crossing of the Rubicon, an indelible step toward departure.
But on Monday, just hours before May's address to Parliament, the EU's highest court ruled that the U.K. can cross back if it wants.
The Court of Justice of the European Union said Monday that the U.K. is allowed to reverse its decision to notify the EU of its intent to leave — and to do so entirely on its own, without the consent of the bloc's other member states.
That window for the U.K. is open so long as it hasn't implemented a final Brexit agreement with the EU — and would remain open until Article 50 was due to take effect in March.
The prospects of a final agreement have grown cloudier by the day.
May's draft deal has taken flak from nearly all sides of the U.K. political spectrum, including from within her own Conservative Party.
The crux of the Conservative frustration rests with the status of Northern Ireland, which is part of the U.K. but also shares an open land border with the Republic of Ireland, an EU member. If London and Brussels can't agree on a future trade relationship, the draft deal establishes an arrangement, known as a "backstop," as a Plan B to determine how customs regulations at that border will work.
Many conservatives have dismissed the draft deal as subjecting the region to unwelcome EU oversight; others have voiced concern about placing Northern Ireland under different rules from the rest of the U.K.
At the same time, some members of Parliament who campaigned against Brexit have called for a second referendum.
And Nicola Sturgeon, Scottish National Party leader and first minister of Scotland, said Monday that if Labour Party leader Jeremy Corbyn introduces a motion of no-confidence in May's government, Sturgeon's party would support the measure.
"We can then work together to give people the chance to stop Brexit in another vote," she tweeted, tagging Corbyn. "This shambles can't go on — so how about it?"
It is not the first time lawmakers have suggested introducing a vote of no-confidence in May. Members of May's own party floated the idea of a no-confidence vote on her leadership of the Conservative Party last month, but it died from a lack of support.
On Monday, responding to the prime minister in the House of Commons, Corbyn did not specifically raise the possibility of a no-confidence vote — but he asserted that confidence in May's negotiations is flagging around the U.K.
"The government is in disarray. Uncertainty is building for business. People are in despair at the state of these failed negotiations and concerned about what it means about their jobs, their livelihood and their communities," Corbyn said. "And the fault for that lies solely at the door of this shambolic government."
The tumult has placed May's government between a rock and a hard place, between those who want to renegotiate the departure deal and others who demand the right to reverse the departure entirely.
Meanwhile, representatives of the European Union have remained steadfast that the draft deal — which European leaders have already approved — is the only one on the table.
"As [European Commission President Jean-Claude] Juncker said, this deal is the best and only deal possible," a commission spokesperson said, according to the BBC. "We will not renegotiate — our position has therefore not changed and as far as we are concerned the United Kingdom is leaving the European Union on 29 March, 2019."
And May told British lawmakers she intends to follow through on that departure.
"Even though I voted Remain," she said, "from the moment I took on the responsibility of being prime minister of this great country, I've known that my duty is to honor the result of that vote."