LONDON — The U.K. home secretary said Thursday there are still “a few discussions to be had” about whether the U.K. will stay in a customs union with the EU post Brexit.

Senior ministers are due to meet next week to discuss the issue ahead of a key House of Commons vote that could put pressure on Prime Minister Theresa May over the U.K. governments decision to exit the union. A nonbinding vote in the house today could give an indication of how much support there is among MPs for such a move.

Leaving the customs union is a central pillar of the governments Brexit strategy because it would allow the U.K. to pursue a trade policy independent of Brussels.

Asked at a lunch with journalists in Westminster whether it was more or less likely the U.K. would stay in the customs union, Amber Rudd said: “We still have a few discussions to be had in a really positive, consensual easy way amongst some of my Cabinet colleagues in order to arrive at a final position.”

Rudd later clarified on Twitter that she “should have been clearer” that “of course when we leave the EU we will be leaving the customs union.”

“I wasnt going to get into ongoing cabinet discussions about our future trading relationship,” she added.

Labours Shadow Brexit Secretary Keir Starmer said: “Amber Rudd appears to have let slip that discussions around the Cabinet table about negotiating a customs union with the EU have not in fact concluded.

“If that is so, then the prime minister should rethink her approach and listen to the growing chorus of voices in parliament, and in the businesses community, that believe she has got it wrong on a customs union.”