U.K. Prime Minister Theresa May faces a series of votes on Tuesday that could change the direction of Brexit.

Two rival factions in Parliament are trying to take control. If one wins, Brexit will probably be put on hold. If the other wins, May would claim a strong mandate to return to Brussels to renegotiate the most controversial part of the divorce deal — the Irish border backstop.

The chances of each side claiming victory depend on whether the relevant amendments are selected for a ballot and how May and Labour leader Jeremy Corbyn order their lawmakers to vote. It’s up to Parliament’s speaker John Bercow to pick which amendments go to a vote — and he has a track record of surprising decisions. He’ll announce which ones he’s chosen on Tuesday.

The Cooper-Boles Delay

Labour’s Yvette Cooper and Conservative Nick Boles are trying to force May to delay Brexit day to avoid crashing out without a deal on March 29. They’re asking Parliament to vote to change its own rules so that, for one day, it can

debate a bill which would require May to seek from the EU an extension of Article 50 until the end of the year.

What it means: If it’s approved, it’s just the beginning of a long parliamentary battle to pause Brexit. It’s positive for business and the pound could rally. It’s also good news for the EU, as it takes no-deal off the table, and means the bloc can continue its strategy of waiting for the U.K. to cave. It probably means a softer Brexit is on the way — and increases the chances of Brexit being reversed.

Chance of passing: High, if Labour supports it. It’s been signed by several Tories who have recently joined the ranks of rebels and are determined to avoid a no-deal Brexit. Boles told BBC Radio on Monday that it has “a great deal of support” among ministers and in Cabinet. The latest Parliamentary order paper lists 103 supporters of the amendment.

Scrap the Backstop

Late Monday, after a week of behind-the-scenes negotiation, May attempted to unite her party by backing a proposal by Conservative backbenchers Andrew Murrison and Graham Brady. It calls for the Irish backstop, the most controversial part of the divorce deal, to be scrapped and replaced with “alternative arrangements.”

What it means: Such an amendment wouldn’t necessarily need to pass to have an effect. If it gained a lot of support from Tory MPs who voted against May’s deal two weeks ago, the prime minister might be able to go back to Brussels and argue that scrapping the backstop would get the deal through. The trouble is the EU has repeatedly said it won’t budge.

Chance of passing: Low. When she endorsed the amendment on Monday evening, May said it would give her a mandate to take back to Brussels. But it had been rejected minutes earlier by the pro-Brexit European Research Group, who said it is insufficiently meaningful. In any case, it might not even get voted on. A similar amendment wasn’t selected for a vote earlier this month and there’s no guarantee this one will be.

Indicative Votes

Labour’s Hilary Benn, who chairs Parliament’s Brexit Committee, wants a series of free-standing votes on the Brexit options, as recommended by his committee. They include a customs union, though not Labour’s exact model.

What it means: More parliamentary maneuvering to try to show what kind of Brexit would command a majority in Parliament.

Chance of passing: Low, even if Labour swings behind it. Benn’s amendment so far seems to have little Conservative support.

Give Parliament Control

Former Attorney General Dominic Grieve, a Conservative and leading campaigner for a second referendum, is asking for six days of Brexit debate over February and March when back-bench members of Parliament are in control. The last of those is March 26, three days before Britain’s scheduled departure from the EU. Like the Cooper-Boles plan, this is designed to give rank-and-file politicians power to direct next steps, and could provide for a last-ditch attempt to avoid a no-deal Brexit.

What it means: More parliamentary shenanigans that could make a soft Brexit, or no Brexit at all more likely. Probably positive for sterling.

Chance of passing: Medium to high, if Labour supports it. It’s been signed by more than 70 MPs, including Tories who aren’t habitual rebels.

Rule Out No Deal

Former Conservative minister Caroline Spelman has teamed up with Labour’s Jack Dromey to propose an amendment that rules out a no-deal Brexit.

What it means: It would be further confirmation that Parliament doesn’t want a no-deal scenario. But the market has probably already priced this in.

Chances of Passing: High, if selected. The House of Commons already indicated in a vote on a Finance Bill amendment this month that a majority of lawmakers oppose a no-deal Brexit. As of Monday, more lawmakers had put their names to this amendment than any other: 129.

Article 50 Extension

Labour’s Rachel Reeves, who chairs Parliament’s Business Committee, is also calling on May to seek an extension to the Article 50 exit process if she hasn’t gotten a deal through Parliament by Feb. 26.

What it means: Good news for business, though it’s not binding in the way the Cooper-Boles amendment aims to be.

Chance of passing: Medium to high, depending again on Labour’s position.

Labour’s Customs Union Or Second Referendum

Corbyn is demanding Parliament hold a vote on different options. His amendment specifies two: staying in a customs union with the European Union (the model Labour favors), and a second exit referendum.

What it means: It would be a surprise if it passes, and would reflect a significant rebellion in Tory ranks. But it would signal a path forward, with a softer Brexit more likely than a second referendum.

Chance of passing: Low. Even Conservative politicians who back a second referendum are unlikely to support something with Corbyn’s name on it. And the Labour leader still looks more wedded to trying to force a general election.

Citizens’ Assembly

Labour’s Stella Creasy and Lisa Nandy want an extension of Article 50 to allow a 250-member so-called citizens’ assembly — selected to be electorally representative — to consider Brexit and make recommendations. Former Labour Prime Minister Gordon Brown has backed the idea in the media.

Chance of passing: Very low. Neither May’s Tories nor the Labour Party support it, and its conclusions would likely immediately be challenged by people who disagreed. Still, the model was adopted by Ireland ahead of its referendum on legalizing abortion.

Second Referendum

Liberal Democrat leader Vince Cable is asking for the government to prepare for another Brexit referendum.

Chance of passing: Very low. The proposal has only been signed by Liberal Democrats and is unlikely to be called. If it were, with neither main party’s leadership backing a referendum, this would do well to get more than 200 votes.