In a hastily arranged speech on Tuesday, the embattled prime minister promised to give members of Parliament a vote on whether to call another referendum to ratify Britain’s divorce from the European Union. It’s something many MPs — including scores in the opposition Labour Party — have been calling for, but she made it conditional on them backing her deal first.

Within minutes of her speech ending, the backlash began. Pro-Brexit Conservative MPs joined the opposition leader Jeremy Corbyn and May’s Northern Irish allies to condemn her proposals. They vowed to vote against them in the House of Commons next month.

The failure of May’s deal would throw the U.K. into renewed turmoil and uncertainty. The outcome of Brexit would be almost impossible to predict as it will be left to May’s successor as Tory leader and prime minister to complete the process.

Leaving the EU with no deal, or even remaining inside the bloc could be back on the table once May is gone. Boris Johnson, who has said he’d be prepared to leave without an agreement, is the front-runner in the leadership race that’s unofficially under way. Johnson was quick to come out against May’s latest plan, as was pro-Brexit rival Dominic Raab.

May’s offer represents possibly the final throw of the dice for a prime minister who has run out of options. Almost three years after the U.K. voted to exit the EU, May’s deal has been rejected three times by Parliament. She’s tried cross-party talks to work out a joint plan with Corbyn but they collapsed last week. Her party is now bracing for defeat in European elections on Thursday — a poll the U.K. wasn’t meant to take part in and has been forced to because Brexit has been delayed.

The pound strengthened after Bloomberg reported the plan for a vote on another referendum, but then reversed its gains to trade 0.2% weaker.

May has promised to put her deal, in the form of a draft law, to a vote in Parliament in the first week of June. Facing overwhelming calls for her to resign, the prime minister has promised to agree to the timetable for her own exit once that vote has taken place. Barring a political miracle, May is headed for a humiliating end to her career.

“I have tried everything I possibly can to find a way through,” May told an audience in central London. “I offered to give up the job I love earlier than I would like.”

The prime minister said that although the cross-party talks with Labour have failed, most members of Parliament still want to deliver the result of the 2016 referendum. Then she set out her offer of “one last chance to do that.”

As part of a 10-point plan, May promised:

A choice for Parliament over the kind of customs model the U.K. should have with the EU after Brexit. A guaranteed vote on whether to call a second referendum to ratify the terms of the exit deal, before Parliament can approve the divorce. Alternative arrangements to mitigate the impact of the so-called “backstop” plan to for avoiding a hard border with Ireland.But first members of the House of Commons will need to vote in favor of May’s overall divorce deal in the first week of June, in what would be the first stage of her bill’s passage through Parliament.

Read More: How Could May Get a Brexit Deal Past Parliament? You Do the Math

Unless Labour MPs support May’s plan, she has little chance of getting it through the Commons vote.

“The Prime minister’s proposal tonight seems to be largely a rehash,” Corbyn said. “We won’t back a repackaged version of the same old deal — and it’s clear that this weak and disintegrating government is unable deliver on its own commitments.”

Free Vote?

Earlier, May held a three-hour meeting with her Cabinet, in which the country’s most senior ministers clashed angrily over her proposals. According to people familiar with the discussions, May made the eye-catching suggestion that Conservatives could be allowed to vote any way they liked on the second referendum question.

But pro-Brexit Cabinet ministers including Michael Gove, Andrea Leadsom and Chris Grayling all voiced their opposition to such a “free vote.” Tory MPs must be whipped against backing a new referendum, they said. Some ministers also forced May to drop plans for offering Parliament a vote on Labour’s proposal for a full, permanent customs union with the EU, the people said.

May’s office said she hasn’t decided yet whether she will tell her party’s politicians how to vote when the referendum proposal comes to Parliament, or let them decide on their own. May has always said she opposes a second referendum as it would be divisive and undermine faith in democracy. DM