LONDON (AP) — British opposition leader Keir Starmer says he will seek a closer relationship with the European Union, but won’t reverse Brexit, if his Labour Party wins a national election that’s due by the end of next year.

Opinion polls put the left-of-center party as much as 20 points ahead of the governing Conservatives, who have been in power since 2010.

Starmer told the Financial Times in an interview that the U.K.-EU trade and cooperation agreement negotiated by the Conservatives is “far too thin.”

“We will attempt to get a much better deal for the U.K.,” he said, adding that the two sides “can have a closer trading relationship as well.”

Britain’s departure from the EU in 2020 remains a divisive political issue. Starmer campaigned to remain in the bloc during the 2016 referendum campaign that was won narrowly by the “leave” side.

Since becoming Labour leader in 2020 he has confirmed that the party will not seek to rejoin the 27-nation EU or try to re-enter the bloc’s single market and customs union, both of which would commit the U.K. to stick closely to EU rules. But he says he will seek to strengthen ties that became strained during testy divorce negotiations.

To an extent, Conservative Prime Minister Rishi Sunak has restored a U.K.-EU relationship that hit rock-bottom under his euroskeptic predecessors Boris Johnson and Liz Truss. He has struck a deal to resolve a dispute over Northern Ireland trade rules, and signed Britain up to the EU’s Horizon Europe science cooperation program. But Sunak is a committed Brexiteer who is wary of getting too close to the bloc.

The Brexit divorce agreement is up for review every five years, starting in 2025. Sunak’s spokesman, Max Blain, said Monday that the Conservative government did not plan to renegotiate the deal “in any way, shape or form.”

As Labour’s consistent poll lead raises the party’s hopes of a return to power, Starmer is making international visits aimed at boosting his profile and connections ahead of a general election in 2024.

He is due in Paris on Tuesday to meet French President Emmanuel Macron. Last week he travelled to The Hague to discuss the fight against people-smuggling gangs with EU police agency Europol and met Canadian Prime Minister Justin Trudeau at a center-left political gathering in Montreal.