Prime Minister Theresa May’s government plans a third vote on Friday on the deal she has agreed to leave the EU, after parliament twice rejected it by large margins.
Andrea Leadsom, Mrs May’s leader in the Commons, parliament’s elected main house, urged lawmakers to back the deal.
The speaker of the Commons, John Bercow, had warned that he might not allow the motion unless it differed significantly from the one that lawmakers had rejected.
But Bercow said the motion for Friday’s vote was “new and substantially different” from the previous two “meaningful votes” on Brexit.
The government said the third vote will cover only Britain’s withdrawal agreement, or “divorce settlement,” and not the separate political declaration on future relations with the EU.
Labour, the main opposition party, said it will vote against the motion and opposes the government’s separation of the two documents.
The motion said Britain “wishes to leave the EU with an agreement as soon as possible and does not wish to have a longer extension” than the agreed end date of May 22 if the withdrawal agreement is approved on Friday.
It said the EU “remains open to negotiating changes to the political declaration” but not the withdrawal agreement.
There were doubts earlier Thursday about whether the vote would go ahead, amid continuing strong opposition to May’s deal from opposition lawmakers and both pro-EU and eurosceptic members of her Conservative party.
Many eurosceptics were angered by May’s decision to request a short delay to Brexit last week.
EU leaders agreed to extend Brexit until May 22, provided the withdrawal agreement is approved by parliament this week.
If it is not approved, they agreed to an extension until April 12, requiring London to “indicate a way forward” before then.
If Britain requests a longer extension, it would have to participate in the EU elections scheduled in late May.
“The only way we ensure we leave in good time on May 22 is by approving the withdrawal agreement by 11 pm on March 29, which is tomorrow (Friday),” Leadsom said.
“We do not want to be in a situation of asking for another extension and of course for the requirement to undertake European Parliament elections,” she said.
Earlier Thursday, a senior Conservative lawmaker said parliament faces a choice between backing May’s deal or a “slightly softer” Brexit that would keep Britain in a customs union with the EU.
The lawmakers rejected eight non-binding motions on alternatives to May’s deal late Wednesday, compounding the uncertainty over Brexit.
Motions on a second Brexit referendum and a plan to stay in a customs union attracted the highest number of votes in favour, but both were narrowly defeated.
“If you want to leave with a deal…. the choice is now between the government’s deal, which I will continue to vote for, or a customs union,” Damian Green, May’s former deputy and long-term friend, said.
May told a meeting of Conservative lawmakers on Wednesday that she will step down once a Brexit deal is finalised, in a bid to rally support for her deal.