The Brexit crisis culminated in a crunch week that either sends Britain sailing nervously out of Europe, or sets the stage for it remaining in. With Britain scheduled to leave the European Union in less than three weeks, U.K. lawmakers are poised to choose the country's direction, at least for now, from among three starkly different choices: deal, no deal or delay.

The House of Commons has a second vote scheduled tomorrow on a deal laying out the terms of Britain's orderly departure from the EU. Prime Minister Theresa May and EU officials agreed to the agreement in December, but U.K. lawmakers voted 432-202 in January to reject it. To get it approved by March 29, the day set for Brexit, May needs to persuade 116 of them to change their minds, a tough task.

Opposition to the deal in Parliament centers on a section that is designed to ensure there are no customs checks or border posts between EU member Ireland and the U.K.'s Northern Ireland. Pro-Brexit lawmakers dislike that the border "backstop" keeps the U.K. entwined with EU trade rules. May has been seeking changes to reassure them the situation would be temporary, but the EU refuses to reopen the withdrawal agreement.

Around 100 hard-core Brexit supporters in May's Conservative Party look set to oppose the deal unless the backstop is altered. To offset them, May has courted the opposition Labour Party with promises of money for urban regeneration.

Nigel Dodds, the deputy leader of the Democratic Unionist Party (DUP) which props up May's minority government, and Steve Baker, a leading figure in the large Eurosceptic faction of her Conservative party, warned "the political situation is grim." "An unchanged withdrawal agreement will be defeated firmly by a sizable proportion of Conservatives and the DUP if it is again presented to the Commons," they wrote in the Sunday Telegraph.

The Sunday Times said May was battling to save her job as aides were considering persuading her to offer to resign in a bid to get the deal approved. The newspaper also said Cabinet ministers have spoken about whether to insist she goes as early as this week.

Britain's opposition Labour Party should support staying in the EU if there is a second referendum, the party's Brexit spokesman, Keir Starmer, said yesterday. "If there's a public vote that would operate as a lock, if you like, on any deal that Theresa May get through. If that is the position, then in my view, the default ought to be 'remain'," Starmer told Sky News.

However, Starmer said the party would not be seeking to secure support in Parliament for a second referendum tomorrow.