The divide is over Europe, and only thing the two feuding factions agree on is that their leader, Prime Minister Theresa May, is heading in the wrong direction.

So May will be under attack from all sides when the Conservatives open their annual conference Sunday in the central England city of Birmingham.

Party conferences are usually a chance for leaders to rally their troops and for parties to unveil new voter-friendly policies. May's goal at this four-day gathering, however, will be surviving atop a fractious and febrile party that is convulsed over Brexit.

"It's simply a case of hoping she emerges from Birmingham without things getting even worse than they are," said Tim Bale, professor of politics at Queen Mary University of London.

May became British prime minister in 2016 because of the Brexit vote in which the country decided to leave the European Union. Her predecessor, David Cameron, resigned when voters rejected his advice and opted to quit the EU after more than four decades of membership. May's entire premiership has been devoted to making Britain's departure happen.

But with exit day — March 29 — exactly six months away, the terms of the divorce and of the U.K.'s future relationship with the EU still remain unclear.

May's Brexit plan proposes that Britain stick close to EU rules in return for remaining in the bloc's single market for goods. EU leaders have rejected that idea, saying the U.K. is trying to cherry-pick benefits of being in the 28-nation bloc without assuming the costs and responsibilities.

The stalemate has emboldened pro-Brexit Conservatives, who say May should ditch her Chequers plan — named for the British leader's country retreat where it was hammered out — and seek a looser trade agreement that leaves the U.K. free to strike new deals around the world.

Flamboyant former Foreign Secretary Boris Johnson, who quit the government in July, on Friday called May's plan "a moral and intellectual humiliation" for Britain.

In a 4,500-word Daily Telegraph article that was as much a Conservative leadership manifesto as a Brexit plan, Johnson said Britain should stop trying to be "half-in, half-out" of the bloc. He argued that the country would be "more dynamic and more successful" once freed from EU control.

Johnson plans to pile pressure on May at a conference rally Tuesday — one of several meetings by Brexit enthusiasts designed to force the prime minister to "chuck Chequers."

On May's other flank are pro-EU Conservatives who want to stay closely bound to the bloc, Britain's biggest trading partner. They want May to keep the U.K. inside the EU's vast single market for goods and services. Some also seek a new referendum that changes the terms of Brexit or even reverses Britain's decision to leave.

This group has been quieter than the "hard Brexit" faction. But many believe support for a softer stance is increasing as the specter of a "no-deal" Brexit grows. If Britain crashes out of the EU without a deal, British shipping, aviation and a host of other areas could grind to a halt.

Simon Allison, chairman of Conservatives for a People's Vote, a group calling for a new referendum on Brexit, said "there are at least as many Tory voters — maybe more — who support our position as support the hard-line (pro-Brexit) position."

The Conservatives are gathering a week after the opposition Labour Party conference , an upbeat, well-organized affair that saw the left-of-center party paper over its own divisions on Brexit and present a united face.

Such unity is unlikely at the Conservative gathering.

Meanwhile, May is digging in. After the EU rejected her Chequers plan last week at a summit in the Austrian city of Salzburg, she blamed the bloc for the negotiating "impasse" and insisted that "no deal is better than a bad deal."

Bale said that the summit gave May some breathing room by creating a sense that she is "under attack from an external enemy — Brussels."

"There is going to be some pressure on Tory MPs to unite behind her in order to send a strong signal to the EU 27," Bale said, referring to the 27 other members of the bloc.

But he said it is "really, really hard to imagine the circumstances" in which May will still be prime minister a year from now.

Many observers expect that May will face a challenge from within her party soon after Brexit day, even if she manages to negotiate a divorce deal that wins approval from the EU, the British Parliament and the Conservatives.

And even that is unlikely to end the party's feuding over Europe — to the despair of many Conservatives, who say the party should be focusing on the British economy, housing, health care and other issues vital to voters.

"Brexit is like a Pac Man that's consuming everything, "Allison said. "And one of the problems is that if we find a fudge on Brexit, that won't stop the debate. We could be having this war for the next 10 years."