Updated Thursday at 9:38 a.m. ET
This week marks a turning point for Britain and Brexit. On Tuesday, the British Parliament voted down Prime Minister Theresa May's Brexit plan for the second time. On Wednesday, lawmakers voted against a "no-deal Brexit" — leaving the European Union without a formal agreement with Brussels.
Today, they will vote on whether to postpone Brexit beyond the scheduled departure date of March 29.
Here's what you need to know.
What happened on Tuesday?
Parliament voted on the prime minister's withdrawal agreement, and it went down to defeat by 149 votes. In a similar vote in January, lawmakers rejected her deal by a historic margin of 230 votes.
The sticking point, as ever, was how to avoid the need for customs posts on the border between Ireland, which is part of the EU, and Northern Ireland, which is part of the United Kingdom. Both sides had agreed to have the U.K. stay inside a customs arrangement to avoid the need for a hard border until they could find another solution.
British lawmakers wanted a time limit on — or a unilateral way to leave — the customs arrangement. But Brussels had repeatedly refused, because if the U.K. left a customs arrangement before it inked a new free-trade agreement with the EU, it would force a return of customs posts, which could provoke conflict, given the border's violent political history.
On Monday, May made a last-minute dash to Strasbourg, France, to meet with EU officials to seek concessions. Afterward, she insisted she'd obtained legally binding reassurances that the U.K. would not become trapped permanently in a customs arrangement. Many British lawmakers feared the U.K. might never escape the clutches of the EU under such an arrangement. "Brexiteers" also argued that remaining inside a customs arrangement would prevent the U.K. from striking new trade deals with other nations.
But on Tuesday, U.K. Attorney General Geoffrey Cox came to a different conclusion, saying the new language from the EU reduced the risk of becoming stuck in a customs arrangement, but did not eliminate it. That legal analysis doomed May's deal.
What happened on Wednesday?
Parliament expressed its opposition to leaving the European Union without a deal at the end of March, or at any other date in the future. The result, 321 votes to 278, was expected, since many ministers and members of Parliament had already warned that leaving the EU without an agreement would lead to economic chaos and hardship for the British people.
The measure was much tougher than Prime Minister May had wanted, but the vote was only advisory, and does not have the force of law unless or until the government introduces legislation to implement it.
What is Thursday's vote about?
Lawmakers will vote on whether to postpone Brexit beyond the March 29 departure date, but there could be a hitch.
Despite the massive defeats to May's Brexit deal, the prime minister is determined to bring it up for yet another vote next week. She has said that if members of Parliament vote her bill down, there could be a long delay — which May has implied could kill Brexit. Some Brexiteers in May's party feel she is putting a gun to their heads, forcing them to vote for her deal or risk never leaving the EU.
If Parliament votes for a delay, it would require all 27 remaining EU countries to agree. The EU has already stated its displeasure with such a prospect. "Why would we extend these discussions?" Michel Barnier, the EU's chief Brexit negotiator, said in the European Parliament on Wednesday morning. "We are at a critical point. The risk of no deal has never been higher. We are ready. The EU is ready to face that situation if we have to."
Brussels, which feels as if it has been asked to solve a domestic British political dispute, would want a clear explanation of how granting the U.K. several more months would solve an issue that has paralyzed Britain's political system.
So what are the chances that the EU would grant an extension?
At the moment, the EU is actually expected to grant an extension. It does not want to look unreasonable or uncooperative. Then it will be up to the two sides to resolve questions of how long the extension would last, and under what conditions it would take place.
On Thursday morning, Donald Tusk, president of the European Council, said he will encourage EU member states to consider a long extension if the U.K. needs to rethink its Brexit strategy and build consensus around it.
May has said if Parliament passes her Brexit deal, the U.K. can ask to extend to June 30, just before a new European Parliament is to be seated. If not, she warns, it could be a much longer — and riskier — delay.
If Parliament votes to postpone past March 29 and has already rejected a no-deal Brexit, does that mean the U.K. will leave the EU with a deal?
Not at all. It's entirely possible there could be a short delay followed by a no-deal Brexit. If that happens, one silver lining is that there would be more time for both sides to prepare to mitigate the expected economic damage.
How long is this going to drag out?
Probably for years. Right now, Brussels and London are only arguing over the so-called divorce arrangement, unwinding more than 40 years of economic integration. After they sort out the terms of withdrawal, they will have to negotiate a new free-trade agreement, which typically takes years — and which analysts say will be even more difficult than what we've been witnessing.
How will Prime Minister Theresa May be judged, and what's her future?
Views of her, at least in Parliament, are at an all-time low and some members of Parliament have been openly contemptuous. Losing two votes by staggering margins on her signature work as prime minister has been humiliating.
On Wednesday night, four of her own cabinet ministers defied her and abstained from a crucial vote. On Thursday, they still have their jobs. Right now, Parliament is in chaos and the prime minister seems to have little control.
That said, a Brexit delay could keep May in office for the next several months. She has already survived votes of no confidence by her own party and Parliament as a whole. May has pledged not to lead her party into the next general election, which is scheduled to be held in 2022.
Producer Samuel Alwyine-Mosely contributed to this report.