Cox said that May’s plan would ‘reduce the risk’ that Britain could be indefinitely trapped in the EU customs union, adding that the legal risk remains unchanged. GBP/USD sheds over 150 pips with the headline.

The future of Britain’s exit from the European Union hung in the balance on Tuesday as lawmakers prepared to vote on a divorce deal after Prime Minister Theresa May won last-minute assurances from the European Union.Scrambling to plot an orderly path out of the Brexit maze just days before the United Kingdom is due to leave, May rushed to Strasbourg on Monday to agree ‘legally binding’ assurances with European Commission President Jean-Claude Juncker.

British lawmakers, who on Jan. 15 voted 432-202 against her deal, were on Tuesday studying the assurances with lawyers. The government’s top lawyer, Geoffrey Cox, is due to give his opinion on Tuesday ahead of the vote due around 1900 GMT.

“We have secured legal changes,” May said in a late night news conference in Strasbourg beside Juncker, 17 days before the United Kingdom is due to leave the EU on March 29.

May 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 the UK and EU to starting work on replacing the backstop with other arrangements by December 2020.

After two-and-a-half years of haggling since the 2016 Brexit referendum, Juncker cautioned this was the last chance for Britain. “It is this deal or Brexit might not happen at all,” he said.

Sterling rose 1.5 percent against the dollar and to a near two-year high against the euro.

If lawmakers vote down May’s deal, she has promised a vote on Wednesday on whether to leave without a deal and, if they reject that, then a vote on whether to ask for a limited delay to Brexit.