• Prime Minister Theresa May’s deal for Britain to leave the European Union faces a crucial test in Parliament on Tuesday — as does the battle-worn Mrs. May herself — in a vote that could shape the nation for generations to come.
• Dealing a blow to the prime minister, the British attorney general, Geoffrey Cox, said new legal language that Mrs. May obtained Monday night from the European Union fell short of providing a mechanism some wanted for Britain to exit the so-called Irish backstop.
• Parliamentary approval of the agreement she negotiated with the E.U. would stand as the greatest victory of Mrs. May’s tenure, making possible a British withdrawal, or Brexit, which is now scheduled for March 29. But defeat, which is seen as more likely, would threaten her hold on power.
• If Parliament rejects the deal, lawmakers would pivot to other votes later in the week, including whether Britain would leave the bloc without any kind of agreement, a so-called no-deal exit.
• The debate is expected to begin around midday on Tuesday, with the vote scheduled for the evening.
Last-ditch effort to salvage the deal
Prime Minister Theresa May made an 11th-hour trip to Strasbourg, France, on Monday, in the latest of a long series of efforts to wring concessions from European Union officials to make the deal more palatable to British lawmakers.
She returned late Monday with some last-minute legal pledges to clarify the temporary nature of the “backstop” plan for the Irish border. Mrs. May hopes the provisions will be enough to win over Brexit supporters in her own party. Skeptics questioned the new pledges on Tuesday as too little, too late, though some Conservatives expressed cautious optimism.
The prime minister has played what amounts to a high-stakes game of chicken, delaying time and again in hopes that the looming deadline will pressure critics on both sides to give in. But Mrs. May faces a very steep climb: Her earlier deal was soundly rejected by 230 votes in the 650-seat Parliament.
To hard-core, pro-Brexit lawmakers — particularly those Mrs. May’s Conservative Party — she has argued that unless her deal is approved, Brexit might not happen at all.
To lawmakers who wanted a softer Brexit — or none at all — she took a different tack, arguing that the choice was between her deal and a potentially chaotic, economically damaging exit without an agreement in place. But allowing a vote on the no-deal scenario may have taken the edge off that threat.
Attorney general says little has changed, a setback for May
But Mrs. May’s prospects of winning the crucial vote were dealt a significant blow late Tuesday morning when the attorney general, Geoffrey Cox, said that the changes she had negotiated did not fundamentally change the legal position.
Mr. Cox said the concessions did “reduce the risk” of Britain’s being trapped in the Irish backstop — an insurance policy to ensure there is no hard border in Ireland, and a main issue for opponents of Mrs. May’s deal.
But Mr. Cox said that the revised agreement did not alter Britain’s rights and obligations. Were there to be a dispute, he wrote, the country would have “no internationally lawful means of exiting the protocol’s arrangements, save by agreement.”
Mr. Cox’s opinion is likely to be influential for pro-Brexit Conservative lawmakers who had been considering voting for the deal, and his views leave Mrs. May’s chances of winning the vote on Tuesday hanging by a thread.
On Tuesday morning, Mrs. May chaired a meeting of the cabinet and told her senior ministers that passing the vote would allow the country to move on to a brighter future, while the alternative would be uncertainty with no guarantee of what happens next. “Let’s get this done,” Mrs. May said, in comments released by her office.
Legal experts are also skeptical
Even before the attorney general had issued his analysis, other legal experts had expressed similar opinions.
Apparently, the most that can be said for the changes is that they reinforce the notion that Britain can opt out of European trading rules if officials in Brussels are found to be negotiating in bad faith.
“In the real world,” wrote Michael Dougan, a professor of European law at the University of Liverpool, “such a prospect should be considered almost entirely theoretical, if not altogether fanciful.”
Three experts in European and international law, commissioned by Brexit opponents to consider Mrs. May’s last-minute tweaks, wrote in an 11-page opinion, “The backstop will endure indefinitely, unless and until superseded by another agreement, save in the extreme and unlikely event that in future negotiations the E.U. acts in bad faith in rejecting the U.K.’s demands.”
What is the Irish “backstop”?
If you don’t understand the Irish “backstop,” you’re not alone.
Confusing in the best of times and loudly debated almost all the time, the Irish backstop is shorthand for the question of how to deal with the border between Ireland, a European Union member country, and Northern Ireland, a part of the United Kingdom, once Britain leaves the European Union.
The backstop would be a way to avoid building a physical barrier with checkpoints for goods — the kind of barrier that the European Union has done away with inside the bloc. The backstop provision of Mrs. May’s Brexit plan says that so long as there is no long-term trade pact, Britain would remain in the European customs union and Northern Ireland would be bound by many of its rules.
Britain could therefore remain tied to the European Union indefinitely without having a voice in shaping its rules — a nightmare scenario for hard-line supporters of Brexit. Mrs. May could cut a deal with the opposition Labour Party for a plan that keeps Britain closer to the bloc, but doing so would put her at risk of alienating her Conservative allies.
If you’d like to learn more about the backstop, you can read our full explanation here.
A linchpin of the deal
At the center of the Brexit issue is the Democratic Unionist Party, a small group of socially conservative, pro-withdrawal lawmakers from Northern Ireland who wield outsize influence because they prop up Prime Minister Theresa May’s government.
The backstop infuriates them not so much because it might trap Britain in the regulatory orbit of Europe, but rather because it might bind Northern Ireland to more European trading rules than it does other parts of the United Kingdom.
That effectively means trade barriers in the Irish Sea, splitting Northern Ireland ever so slightly from the rest of the United Kingdom. That’s unacceptable to unionists, for whom the link to Britain is sacred. The D.U.P. would rather kill the backstop and risk a hard border between Northern Ireland and the Republic of Ireland.
The 10 D.U.P. lawmakers were coy early Tuesday about the tweaks that Mrs. May had obtained. But after Britain’s top lawyer said the new language didn’t substantially change the backstop arrangement, the government’s slim hopes of winning them over quickly deflated.
The Belfast Telegraph reported that the D.U.P. saw the legal advice as “not exactly a ringing endorsement.” Other news outlets said D.U.P. officials saw no way that they could support the deal.
What happens if Parliament rejects the deal again?
If Parliament rejects Mrs. May’s deal on Tuesday, the focus would then shift to a vote scheduled for Wednesday on whether to oppose leaving without a deal, a move that would most likely require pushing back the originally scheduled departure date of March 29.
Some hard-line Brexiteers insist that they would welcome a no-deal split as a clean and complete break from the European Union. But it is clear that most members of Parliament see it as more akin to driving over a cliff.
Formal opposition in Parliament to a no-deal departure would ratchet up pressure on the government to seek a postponement of the deadline, something that would be contingent on an agreement between Mrs. May’s government and the European Union.
The government could evade the March 29 deadline unilaterally, but only by revoking its decision to leave the European Union, a step that Mrs. May has insisted she will not take. But postponing or revoking Britain’s departure would give new hope to those who want to call a second referendum.
The 2016 referendum won with 52 percent of the vote, but Brexit opponents hope that circumstances have changed enough to reverse the result.
Theresa May has already suffered a string of humiliations
If Parliament hands Mrs. May an embarrassing defeat on Tuesday, it would at least be a familiar experience.
Prime ministers rarely lose significant votes in Parliament, but Mrs. May has survived several Brexit-related setbacks that would ordinarily spell the end of a leader’s tenure, to say nothing of a stream of cabinet resignations.
Last fall, Parliament forced Mrs. May, over her objections, to publish both its legal and economic analyses of Brexit.
In December, lawmakers voted for the first time in history to find the government in contempt of Parliament, for resisting the release of the legal advice.
Days later, Mrs. May postponed a vote on her Brexit deal, admitting that it would lose “by a significant margin.”
Not since the early 1990s had a prime minister faced a vote of no confidence, either from her own party or from Parliament as a whole, but in the last three months, Mrs. May has experienced both.
But she suffered a series of defeats on Brexit-related votes in January, culminating in the 432-to-202 rejection of the Brexit deal that she had negotiated with the European Union.
In February, she called a Parliamentary vote to endorse her negotiating position — and lost, 303 to 258.
She’s still standing, but it is not clear how much more she can take.