LONDON • British Prime Minister Theresa May was set to present a new divorce deal to Parliament after she won last-minute assurances from the European Union on a major sticking point, but by press time had failed to win over the main Brexit faction in her Conservative Party.

In a last-ditch bid to plot an orderly path out of the Brexit maze just a couple of weeks before Britain is due to leave the EU, Mrs May rushed to Strasbourg, France, on Monday to agree on legally binding assurances on the controversial Irish backstop with European Commission president Jean-Claude Juncker.

The main sticking point is the so-called Irish border backstop, an insurance policy aimed at avoiding controls on the border between the British province of Northern Ireland and EU member Ireland after Brexit.

This will be a critical week for Brexit in the British Parliament. If lawmakers vote down Mrs May's deal again, they will be given a vote today on leaving without a deal, and if they turn down that option they will vote tomorrow on delaying Brexit.

Mrs May had announced three documents - a joint instrument, a joint statement and a unilateral declaration - which she said were aimed at addressing the most contentious part of the divorce deal she agreed with the EU last November.

She said the assurances created an arbitration channel for any disputes on the backstop, "entrenches in legally binding form" existing commitments that it will be temporary and binds Britain and the EU to starting work on replacing the backstop with other arrangements by December next year.

In essence, the assurances give Britain a possible path out of the backstop through arbitration and underscore the EU's repeated pledges that it does not want to trap Britain in the backstop.

But British Attorney-General Geoffrey Cox yesterday said in a written opinion that the assurances left the legal risk of Britain being locked in the bloc's orbit after the country's departure, a key issue for Brexit-supporting lawmakers.

"The legal risk remains unchanged," Mr Cox said. "However, the matter of law affecting withdrawal can only inform what is essentially a political decision that each of us must make."

The main pro-Brexit faction in Mrs May's party, the European Research Group, said it did not recommend voting for her deal.

It said the verdict of its "Star Chamber" set up to analyse the assurances was that they did not deliver legally binding changes to the Brexit deal or the Irish backstop and did not provide an exit mechanism over which Britain had control.

"In the light of our own legal analysis and others, we do not recommend accepting the government's motion today," said senior pro-Brexit Conservative Party lawmaker William Cash.

Brexit-supporting lawmakers expressed suspicion at the haste of Mrs May's last-minute assurances and suggested a delay to allow sufficient analysis of them and Mr Cox's advice. "I am very, very suspicious and concerned about the time scale," said Conservative Party lawmaker Andrew Bridgen. "The ink isn't even dry on the agreement... And we've got to vote on it today."

Mr Nigel Dodds, parliamentary leader of the Northern Irish Democratic Unionist Party, which props up Mrs May's minority government, said the assurances would still trap Britain in the EU's orbit.

The sterling fell as much as two cents on Mr Cox's advice, which was seen as reducing the chance that Mrs May's deal will be approved by Parliament.

British lawmakers, who on Jan 15 voted 432-202 against Mrs May's deal, was expected to vote at 7pm local time yesterday (3am Singapore time today).

Mr Juncker cautioned that after 2½years of haggling since the 2016 Brexit referendum, this was Britain's last chance. "It is this deal or Brexit might not happen at all."

German Chancellor Angela Merkel said the EU had made far-reaching proposals to Britain on Brexit to ease its concerns and this was the final offer.

Britain's labyrinthine crisis over EU membership is approaching its finale with an array of possible outcomes, including a delay, a last-minute deal, a no-deal Brexit, a snap election or even another referendum.

Brexit will pitch the world's fifth-largest economy into the unknown and many fear it will divide the West as it grapples with both the unconventional leadership of United States President Donald Trump and the growing assertiveness of Russia and China.

Supporters of Brexit say that while the divorce might bring some short-term instability, in the longer term it will allow Britain to thrive and also enable deeper EU integration without such a powerful reluctant member.

Mrs May, an initial opponent of Brexit who won the top job in the chaos following the 2016 referendum, has repeatedly warned that Brexit could be thwarted if lawmakers reject her deal.

REUTERS