The future of Brexit could be decided in the UK Parliament on Tuesday. But it probably won’t be.

Members of Parliament are expected to vote January 15 on the Brexit withdrawal agreement, which Prime Minister Theresa May and her counterparts in the European Union negotiated in November. The vote had initially been set for December, but May abruptly postponed it when it became clear that her deal was headed for a crushing defeat.

Now May’s government will try again, but it doesn’t look like much has changed in the past month. The prospects of getting her deal through Parliament still look grim. The withdrawal agreement — which outlines the terms of the EU-UK divorce — remains unpopular with just about everyone, from the hardline Brexiteers who want a decisive split with Europe to the pro-Remain camp who want to stay close to the EU.

On Monday, May made a last-ditch attempt to sell the agreement ahead of the vote. She argued that despite objections from all corners, this deal is the only way to ensure an orderly Brexit. “So I say to Members on all sides of this House — whatever you may have previously concluded — over these next 24 hours, give this deal a second look,” May told members of Parliament. “No, it is not perfect. And yes, it is a compromise.”

That doesn’t look like it will be enough to persuade Parliament, even though the Brexit deadline of March 29, 2019, is just two months away. If the UK hasn’t ratified a withdrawal agreement by that date, it will crash out of the EU, with potentially catastrophic consequences, from food and medicine shortages to major backlogs at ports of entry.

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If May’s deal is defeated, she’ll have to come back to Parliament with a “plan B” — but no one knows what that would look like at this point. May didn’t rule out the possibility of extending the Brexit deadline on Tuesday, and there are signs that the EU also might be willing to extend Britain’s exit, if it looks like there’s another alternative to no deal.

But more time doesn’t put the bitterly divided UK any closer to a solution on Brexit. Members of Parliament have proposed other solutions — such as holding another referendum to decide the future of Brexit — but that’s only complicated the political stalemate, as alternatives lack consensus right now.

The opposition Labour Party, for its part, has said that it will call for a no-confidence vote in May’s government if her deal is badly defeated. While it’s unclear if the gambit will succeed, it would likely thrust May into political turmoil once again.

Right now, May’s deal appears headed for defeat — though it’s unclear if it will be a hugely embarrassing one, or if it will leave her room to salvage the plan and attempt another vote. Either way, one thing is for sure: Britain is bracing for more uncertainty and political chaos.

The Brexit deal everyone hates, briefly explained

May’s Brexit deal lays out the terms of the UK’s divorce from the European Union. It’s nearly 600 pages long, but one of the key elements of the agreement is that it provides a 21-month transition period (which can be renewed up to one time), during which the UK will lose its decision-making power in the EU but will remain part of the body and follow all its rules. During this period, the EU and UK will also negotiate the terms of the future trade relationship, which is currently outlined in a short political declaration attached to the withdrawal agreement that’s intentionally open-ended.

The opposition to the deal is fierce. The hard Brexiteers — those who want a clean break from the EU — see this document as potentially trapping the UK in a dependent relationship with the bloc indefinitely. Meanwhile, members of Parliament who are pro-Europe, or ultimately want to Remain, view the deal as weakening the UK and leaving it in a much worse position economically and politically.

The primary issue with the deal, particularly for the Brexiteers, is what’s known as the “Irish backstop,” which is basically an insurance policy to guarantee that the border between Northern Ireland (which is part of the UK) and the Republic of Ireland (part of the EU) remains open as the UK and EU try to negotiate their future relationship.

That open border is a critical facet of the Good Friday Agreement, which ended a decades-long sectarian conflict. The current deal seeks to preserve this open border through a complicated arrangement whereby the UK remains part of the EU customs union and Northern Ireland joins in some elements of the single market, which refers to the four fundamental freedoms of the EU: free movement of people, services, capital, and goods.

The backstop only goes into effect if the UK and EU can’t figure out their future relationship in that transition period. The UK can’t unilaterally pull out of this setup, and given how Brexit has gone, people are convinced that this is going to take years to sort out. That would mean the backstop could very well kick in. For the pro-Brexit crowd, this is a betrayal of Brexit because it means the UK can never truly break free from EU regulations.

May has tried to ask the EU for a way to exit the backstop unilaterally. The EU has been firm that the answer is no but has tried to offer last-minute assurances too. In a letter sent to May on Monday, European Commission President Jean-Claude Juncker and European Council President Donald Tusk said that the EU “does not wish to see the backstop enter into force.”

It doesn’t seem as if this letter will do much to sway Parliament, even though the EU has been consistent — it’s this Brexit deal, no Brexit deal, or no Brexit at all.

Some in Parliament are still holding out hope that the deal can be renegotiated, though this is a somewhat disingenuous argument. The withdrawal agreement sets the terms of the divorce, and the EU is always going to insist on a backstop for the Irish border in any deal.

“The point is, you still need the withdrawal deal,” Matthias Matthijs, a professor of international political economy at Johns Hopkins University, told me. “The beauty of the political declaration, which is nonbinding, is that [the UK] can pretty much do everything they want once they’re out. They can be as close or as far as they want; that’s up to the British government to negotiate.”

May’s deal looks like it’s headed for defeat — but what happens next is anyone’s guess

May’s deal is almost certainly going down. At least 100 Conservative MPs — members of May’s own party — have said they’re voting against it.

Some British political observers believe that if the deal fails by double digits (say, 40 or 50 votes) in a 650-member Parliament, May might be able to salvage the deal in a second vote. But if this is an embarrassing triple-digit thrashing, the future of the deal — and May’s political future — is on the line.

What actually happens after Parliament votes down this deal is really anybody’s guess. There are a couple of things to watch for.

Something happens in Parliament

Members of Parliament can offer amendments on the day of the vote, which might alter May’s deal or offer solutions if the deal fails, such as taking measures to avert a no-deal outcome. If the deal is defeated, MPs can also try to take more control over the Brexit process after May comes back to them with a “plan B,” which she’s required to do. They may get more say over the Brexit process — though the very divided Parliament would need to come up with a solution.

May faces a no-confidence vote — and Britain hosts general elections

There’s a possibility that May could resign if the deal is soundly defeated. She also may face a no-confidence vote from the entire Parliament. This is different from the no-confidence vote May survived in December, which was strictly within her own party.

Jeremy Corbyn, the leader of the opposition Labour Party, has said that he will seek one “soon.” But the gambit might be risky. Conservative Party members or members of the Democratic Unionist Party, a Northern Ireland party that props up May’s government, would have to defect. While they might not love May’s deal, they probably hate the idea of Corbyn becoming prime minister even more.

If May loses, members have 14 days to try to form a new government, and if they can’t, then general elections would be called. A huge chunk of the Labour Party wants to make a second referendum — a people’s vote on the future of Brexit — the party’s platform, but Corbyn has resisted, and says instead that he’s going to renegotiate the Brexit deal.

If general elections do happen, they would take five to six weeks, and it’s likely Britain would have to get permission from the European Union to extend Article 50 (the mechanism of the EU treaty that the UK used to withdraw from the bloc) and push back the Brexit deadline.

May could try again. Seriously.

An amendment passed last week requires May, if her deal is defeated, to come back to Parliament with a “plan B.” But as Anand Menon, a Brexit expert with the UK in a Changing Europe initiative, told me, “Plan B is to do plan A again.”

Again, a lot of this will depend on how close the vote is. If May’s deal isn’t defeated that badly, then she may be in a stronger position to go back to Brussels and maybe eke out a few concessions or legal guarantees from the EU — specifically something called a “joint interpretative instrument.” That would basically give the Irish backstop the force of international law, which, in May’s estimation, would help dispel the “hard Brexiteer” notion that the backstop is some trap set by the EU to keep the UK down.

The EU has resisted, but they might relent if they believe it would legitimately push the deal through. It will, again, depend on the margin of the vote. As Menon told me, the EU is not “going to spend their political capital on a dead-duck prime minister.”

Parliament tries for a second referendum

There’re been growing support for a second referendum — it has cross-party support in Parliament, but not quite a majority. May has resisted such a vote at all turns, suggesting it’s undemocratic and effectively voids the outcome of the 2016 referendum.

Proponents of a second referendum believe that enough voters will have witnessed the Brexit mess and will opt to remain part of the EU on a second try. Their case was bolstered by a decision by the European Court of Justice last month that said the UK could unilaterally revoke Article 50 and basically cancel Brexit altogether, without the approval of the other 27 EU member states, and as long as it remained consistent with UK laws.

But a second referendum is enormously risky, and it’s not clear what it would ask: a vote on May’s Brexit deal? A Leave or Remain do-over vote? This would also require an Article 50 extension, pushing back the Brexit deadline. And even though it’s seen as a possible Brexit do-over, there’s no guarantee that pro-Remainers would get the outcome they desire.

There’s always the chance of a no-deal Brexit

If May’s deal fails and Parliament can’t come to a consensus on what to do next, the UK will continue to hurtle toward the Brexit deadline without a deal. The government has stepped up contingency planning in recent weeks, but it may not be enough to absorb the economic and political shock of this scenario, which would likely include food and medicine shortages, flights grounded, ports of entry backed up for miles, and troops deployed.

The deal that won’t die?

The Brexit debate has paralyzed British politics, and the myriad outcomes — second referendum! no deal! general elections! — means the future of Brexit is frustratingly uncertain.

There is also always the chance, however slim, that May’s deal will pass. Then Parliament would have to pass legislation to make elements of the agreement law ahead of the March 29 deadline. It can also kick off the process of negotiating the terms of the future EU-UK relationship.

And even if May’s deal is defeated on Tuesday, the prime minister can resurrect it. As May said in her address to Parliament, the deal isn’t perfect — but it is a compromise.

However, no one seems to want to compromise right now, because they haven’t given up hope that their side might prevail. (If this sounds familiar, it should.) The “no” votes of Conservative and Labour MPs are less a rejection of May’s deal than a last-chance effort to get a different outcome. Pro-Remainers are still seeking a way to undo Brexit, and pro-Leavers know the default is no deal — an outcome they can live with if it achieves the goal of breaking up with the EU for good.

Those options will start to dwindle as the Brexit deadline nears, especially if a majority of Parliament wants to avoid a no-deal scenario. That’s pretty much been May’s argument all along: If Britain wants to break up with the EU, then this deal is the only way forward. And May could still win.

“There’s life left in the deal yet,” Menon said. “Not an awful lot, but it’s certainly not dead.”