May’s Brexit plan rejected amid her waning authority

The European Commission rejected British Prime Minister Theresa May’s emerging plan for a post-Brexit trade deal, just as she tries to persuade her divided Cabinet to back it during a marathon meeting that has been billed as a showdown.

Ms. May is meeting with her most senior ministers to try to force them to agree the outline of a trading policy that would see the U.K. remain close to EU rules in many areas — such as carmaking and data sharing — while breaking away partially or fully in others, an approach known as the “three baskets.”

It won’t work, the commission said in a presentation published on its website.

“U.K. views on regulatory issues in the future relationship including ‘three basket approach’ are not compatible with the principles in the European Council guidelines,” one of the slides reads. If Britain” aspires to cherry pick,” there’s a “risk for the integrity” of the single market, it says.

The EU Commission’s assessment outlines the difficulties of reaching trade terms with the U.K. in areas including chemicals, agriculture and carmaking. Despite U.K. proposals for a system of “mutual recognition” of British and European regulations, the document suggests this would represent exactly the kind of “cherry picking” approach it has always ruled out.

The intervention comes at a critical time in the Brexit process, with Ms. May’s authority under pressure and time for negotiations running short. The European Union leaders meet without Britain Friday looking to plug a major budget hole after Brexit and endorse a plan to streamline the European Parliament by sharing out the country’s seats.

In an implicit warning to Britain, EU Council President Donald Tusk, who chairs the summit, says he will inform leaders how he plans to draw up the guidelines for future relations with their departing partner.

Britain is set to leave the EU — the first country to exit the world’s biggest trading bloc — on March 29, 2019. But Brexit talks must be finalized by this fall so parliaments can ratify any withdrawal agreement.

EU leaders have appealed for Britain to explain its vision of their future ties, but few details have emerged. Mr. Tusk is ramping up the pressure, saying he wants things made clear by the next EU summit on March 22-23, just a month away.

In Britain, the Conservative party is even more divided than Ms. May’s Cabinet. Dozens of Tory hardliners warned Ms. May in a public letter not to cave during upcoming clinch negotiations with Brussels. They want Britain to have a complete, clean, clear exit from the European Union — or else. Supporters of a softer, gentler Brexit, including highranking conservative allies of Ms. May, called their demands “a ransom note.”