Britain’s Prime Minister, Theresa May, has made an appeal to opposition Labour leader Jeremy Corbyn for a compromise Brexit plan – in comments that are certain to enrage lawmakers within both severely fractured parties.

May dropped her strongest hint yet that she is close to reaching an agreement with Corbyn, writing in the Mail on Sunday newspaper that the two should “put their differences aside” and get a Brexit plan over the line in the House of Commons.

But time is running out for a plan to be passed before this month’s European elections, and any such agreement — likely to include a customs arrangement with the European Union — would enrage hardliners in her own Conservative ranks, potentially prompting a showdown over her leadership.

“To the leader of the opposition, I say this: let’s listen to what the voters said in the local elections and put our differences aside for a moment,” May wrote. “Let’s do a deal.”

Mrs May’s party received a drubbing in local polls this week and Labour also suffered losses, which May said gave “a fresh urgency” to ongoing cross-party talks.

“We cannot now shrug our shoulders and say it’s all too difficult,” she wrote.

“We have to find a way to break the deadlock.”

There’s however, no guarantee a compromise plan would achieve a majority in the House of Commons, as Corbyn would also face a backlash from within his party if he agreed to help May secure a withdrawal from the EU.

The Labour leader, a longtime euro-skeptic, has faced pressure from much of his bloc to push for a second referendum, and acquiescing to May’s pleas without that stipulation would alienate a significant proportion of his lawmakers and the party’s membership.

“The country will never forgive Labour if we make a stitch-up Brexit with the Tories in the backrooms of Westminster,” the party’s MP David Lammy said on Saturday, demonstrating the unease with the plan on the party’s backbenches.

Britain is currently set to leave the European Union on October 31, having twice pushed the date back. But if a cross-party plan were passed by May 22, the withdrawal could take place earlier and the country would not have to hold European elections at the end of the month.

The two camps have been negotiating over Brexit for weeks, and speculation has been growing in recent days that a plan is close to coming together.

Their meetings, called by May after her deeply unpopular Withdrawal Agreement was crushed by lawmakers for a third time in March, were initially seen as a half-hearted effort unlikely to pull Britain out of its paralyzing Brexit impasse.

More recently, however, senior figures on both sides have talked up the possibility of a compromise emerging, and May described the talks as “serious” in her Sunday column.

“We don’t agree with the Opposition on lots of policy issues, but on Brexit there are areas we do agree on — leaving with a good deal that protects jobs and our security and ends free movement,” she added.

The Prime Minister’s refusal to take Britain out of the bloc without a deal — an outcome economists warn would cause severe damage to the economy — has angered several pro-Brexit MPs, with former Tory leader Iain Duncan Smith calling on her to stand down after the party’s huge local election losses.

She acknowledged that anger in her column, writing that many in her party find the cross-party talks “uncomfortable.”

“Frankly, it is not what I wanted, either,” she added.

If a plan is not passed by May 22, May’s party is on course to take a further hit in the upcoming European elections.

Nigel Farage, the chief Brexit architect whose new Brexit Party is significantly outperforming the Conservatives in opinion polls, on Sunday said that a cross-party plan could destroy both the Tory and Labour parties.

“This will be the final betrayal,” he told Sky News, adding that “millions of people will give up on both the Labour and Conservative party” if a plan is reached.

“And quite frankly if [Prime Minister Theresa] May signs up to this I can’t even see the point of the Conservative party even existing, you know — what’s it for?” Farage said.