Britain’s main opposition Labour Party said Tuesday it will reject Prime Minister Theresa May’s proposed Brexit deal with the European Union when it comes to a vote in Parliament, saying the government was offering the country a choice between “really bad and even worse.”

“We do not accept that the choice is between whatever the prime minister manages to cobble together and no deal … between really bad and even worse.”

If Britain and the EU agree on a deal, it must be approved by individual nations before Britain leaves. In the U.K. that means a vote by lawmakers, and the math looks ominous for May’s government, which lacks an overall majority.

Brexit spokesman Keir Starmer told Labour’s annual conference that the party would vote against a deal along the lines May is proposing because it does not meet “six tests” it has set, including protecting workers’ rights and retaining access to European markets.

“We do not accept that the choice is between whatever the prime minister manages to cobble together and no deal … between really bad and even worse,” Starmer said.

Starmer said that if Parliament rejected the deal there should be a new election.

“If that is not possible we must have other options,” he said. “Our options must include campaigning for a public vote — and nobody is ruling out ‘remain’ as an option.”

Starmer’s suggestion that a new referendum could reverse the 2016 decision to leave the EU — which was not in the printed text of his speech released in advance — drew a standing ovation from many delegates in the conference hall.

Labour leader Jeremy Corbyn has long opposed the idea of a new referendum, saying the party must respect voters’ decision to leave.

But with Britain due to exit the EU in six months, on March 29, and negotiations at an impasse, Corbyn is under intense pressure from members to change course.

Conference delegates are expected later Tuesday to back a compromise motion leaving the option of a second referendum open, but not calling for it directly.

EU leaders rejected the Conservative government’s blueprint for future trade ties at a fractious summit in the Austrian city of Salzburg last week.

May’s plan seeks to keep the U.K. in the EU single market for goods but not for services, in order to ensure free trade with the bloc and an open border between the U.K.’s Northern Ireland and EU member Ireland. But EU officials say that amounts to unacceptable “cherry-picking” of elements of membership in the bloc without accepting all the costs and responsibilities.

The Salzburg rebuff left May under siege from Brexit-supporting Conservatives, who want her to seek a looser relationship based on a bare-bones free trade agreement that would leave Britain free to strike new deals around the world.

For now, May is sticking by her plan. After a meeting of the divided Cabinet on Monday, May’s Downing St. office said hers is “the only plan on the table … and she remains confident of securing a deal with the EU.”

German Chancellor Angela Merkel warned Tuesday that time is tight. An EU summit next month is seen as a make-or-break moment for a Brexit deal.

Speaking in Berlin, Merkel said there were “six to eight weeks of very hard work in front of us in which we must take the political decisions.”

“Of course, to a significant extent this also depends on what Britain really wants — the discussion isn’t so clear here,” she said.

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