Updated January 15, 2019 06:32:45

Photo: Mrs May argued that defeating the deal could open the way for EU-backing legislators to block Brexit. (AP: Ben Birchall/PA)

British Prime Minister Theresa May has offered both a promise on workers' rights and a reassuring letter from European Union leaders as she implored British politicians to support her floundering Brexit deal.

But the British leader had few concrete measures up her sleeve a day before a vote in Parliament which looks likely to see her Brexit deal rejected.

A defeat on Tuesday would throw Brexit plans into disarray just weeks before the UK is due to leave the bloc on March 29.

Mrs May warned that the only alternatives to her agreement were an economically damaging, chaotic "no-deal" exit from the EU or a halt to Britain's departure that would defy British voters' decision in 2016 to leave the bloc.

In a speech Monday at a ceramics factory in the central England city of Stoke-on-Trent, Mrs May said "people's faith in the democratic process and their politicians would suffer catastrophic harm" if her deal is rejected and Brexit was abandoned.

Having Britain leave the EU without a deal "would cause turbulence for our economy, create barriers to security cooperation and disrupt people's daily lives," she said.

"The only deal on the table is the one (members of Parliament) will vote on tomorrow night," Mrs May said.

May seeks reassurances from EU leaders

Britain and the EU reached a hard-won divorce deal in November, but the agreement has run aground in the UK Parliament.

Photo: Mrs May said she has received further assurances about her Brexit deal from the European Union. (AP: Frank Augstein)

Mrs May postponed a vote on the deal in December to avoid a resounding defeat, and there are few signs the deal has picked up much support since then.

Several previously opposed British legislators have swung behind Mrs May's agreement in the last few days, but they remain outnumbered by those determined to vote against it.

Brexit talks have all but stalled over the vexed issue of the Irish border — the most contentious aspect of any potential exit deal.

In a bid to win support, Mrs May sought reassurances from EU leaders about the deal's most contentious measure — an insurance policy known as the "backstop" that would keep Britain in an EU customs union to maintain an open border between Northern Ireland and EU member Ireland after Brexit.

Pro-Brexit politicians worry that Britain could be trapped indefinitely in the backstop, unable to strike new trade deals around the world.

In a letter to Mrs May published Monday, European Council president Donald Tusk and European Commission president Jean-Claude Juncker offered an assurance that the backstop "would only be in place for as long as strictly necessary".

They promised that the EU would work quickly to strike a permanent new trade deal with Britain that would render the backstop unnecessary.

But the letter also reiterated the bloc's refusal to renegotiate the divorce deal.

The two men said "we are not in a position to agree to anything that changes or is inconsistent with the Withdrawal Agreement".

'The end game'

Mrs May warned politicians on Sunday that failing to deliver Brexit would be "catastrophic" for democracy, and her ministers said that thwarting the outcome of the 2016 referendum could lead to rise in far-right populism.

Photo: Politicians are due to vote on the agreement Tuesday, and all signs suggest they will reject it. (AP: Frank Augstein)

With no-deal Brexit the default option if Mrs May's deal is defeated, some politicians are planning to pull control of Brexit from the government.

Rather like a computer game, once you escape one level of the Brexit game the next is even harder. But unlike a computer game, you can't turn Brexit off, as a weary country is finding, writes Nick Rowley.

Though Mrs May is weakened, the executive has significant powers, especially during times of crisis, so it was unclear how parliament would be able to take control of Brexit.

If Mrs May's deal is defeated and the government is unable to have any amended version passed in the next three weeks, one suggestion is for senior politicians who chair parliamentary committees to come up with an alternative Brexit plan.

"We're in the very, very final stages of the end-game here," said Nick Boles, one of the Conservative politicians behind the plan, who said he would vote for Mrs May's deal.

"What we need to do is find the solution, and if the government can't find the solution — and we want the government to find the solution, and we'll be voting for her solution — but if it can't then parliament needs to."

Wires

Topics: world-politics, government-and-politics, foreign-affairs, agreements-and-treaties, united-kingdom, european-union

First posted January 15, 2019 01:28:54