LONDON — British Prime Minister Theresa May told skeptical lawmakers on Wednesday that rejecting her divorce deal with the European Union would mean uncertainty and division, before a meeting with European Commission President Jean-Claude Juncker to help finalize the Brexit agreement.

The U.K. and the European Union agreed last week on a 585-page document sealing the terms of Britain’s departure, but are still working to nail down agreement on future relations so that EU leaders can meet in Brussels on Sunday to rubber-stamp the package.

With wrangling continuing on issues including Gibraltar and fishing rights, European Commission Vice President Valdis Dombrovskis said Wednesday that the political declaration on future relations was “not there yet.”

He said diplomats would meet Friday to prepare for Sunday and “they will need to see a final text before then.”

“The Commission stands ready to consider the text and take any action at any time,” he said.

At home, May is under intense pressure from pro-Brexit and pro-EU British lawmakers, with large numbers on both sides of the debate opposing the divorce deal. Some think it will leave the U.K. tied too closely to EU rules, while others say it will erect new barriers between the two.