With her agreement facing almost certain defeat in a House of Commons vote on Tuesday, May will make an 11th-hour appeal with a warning that there’s now more chance of members of Parliament blocking Brexit than of Britain leaving the European Union without a deal.

“What if we found ourselves in a situation where Parliament tried to take the U.K. out of the EU in opposition to a remain vote? People’s faith in the democratic process and their politicians would suffer catastrophic harm,” May will say in a speech in Stoke-on-Trent on Monday, according to extracts released by her office. “We all have a duty to implement the result of the referendum.”

Her choice of Stoke is significant. The city in central England, 135 miles (217 kilometers) north of Parliament in London and once the heart of the global pottery industry, voted more emphatically to leave the EU than anywhere else in the U.K. in the 2016 referendum.

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May’s warning comes after the Sunday Times reported that some lawmakers are planning to seize control of the legislative agenda from the government in an act that would allow Parliament to extend the March 29 Brexit deadline or even overturn the decision to leave the EU.

A senior government official on Sunday described the plan as extremely concerning, since if it succeeds lawmakers would gain control over not just Brexit legislation but all legislation.

May has 24 hours to save a deal with the EU that’s taken almost two years to negotiate, but the task looks virtually hopeless. The premier appears no closer to getting the backing she needs than she was in December, when the vote was dramatically pulled before it could be rejected. The question now is what she should do next.

A defeat would leave Britain on course to leave the EU with no new trading arrangements in place. According to Bank of England analysis, such a chaotic split could hammer the pound and home prices, and plunge Britain into a recession worse than the financial crisis a decade ago.

Brexit-backers argue that May should go back to the EU and renegotiate the most contentious parts of the deal before putting a revised agreement to a vote, though Brussels has indicated there’s little room for compromise. Senior ministers are also said to be urging May to seek a joint plan with the opposition Labour Party, raising the possibility of a significantly softer Brexit.

Labour, meanwhile, wants to topple the government by forcing a general election, and on Sunday leader Jeremy Corbyn indicated his party could bring a no-confidence ballot within days if May loses the vote on her Brexit deal. His chance of victory is slim, however, and failure would put him under pressure to back the growing cross-party calls for a second referendum. That, in turn, risks a backlash from the many Labour supporters who voted to leave the European Union.

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The EU is waiting to see the outcome of Tuesday’s vote — and the margin of the expected defeat — before considering its response, officials said, with some predicting that May will have to delay Brexit.

A margin of defeat exceeding about 60 lawmakers would probably mean the agreement is close to death and negotiations are in uncharted waters, several EU officials said. A narrower defeat and the bloc may look at fresh ways of making the deal palatable to get it across the finish line in Parliament.

The EU is expected to publish a letter on Monday in which the bloc will reiterate that the so-called Irish backstop arrangement, if it is triggered, will only be temporary. But the contents are unlikely to appease Brexiteers who fear Britain will end up being tied to EU trade rules indefinitely. DM