Boris Johnson just resigned over Brexit talks. Prime Minister Theresa May could be in trouble.

British Foreign Secretary Boris Johnson has resigned from the British government to protest Prime Minister Theresa May’s plans for a “soft Brexit.”

He’s the third and most prominent minister to resign in 24 hours over May’s handling of Brexit — a dramatic and destabilizing gesture that illustrates just how divided her cabinet is over how to navigate the country’s departure from the European Union.

News of Johnson’s departure came just hours after David Davis, the cabinet minister directly responsible for overseeing the Brexit process, resigned on Sunday evening.

Davis said that May’s vision for Brexit ceded too much control to the European Union. “It seems to me we’re giving too much away, too easily, and that’s a dangerous strategy at this time,” he told BBC Radio on Sunday.

Shortly thereafter, the minister of the “Department for Exiting the EU,” Steve Baker, quit as well.

Johnson, Davis, and Baker are advocates for a “hard Brexit”; they favor a more complete break from the EU. May and other members of her cabinet are more inclined to a “soft Brexit” that entails striking a deal that allows the UK to keep closer ties to the EU after Brexit is complete in 2019.

In the wake of the resignations, British finance minister Philip Hammond tweeted on Monday that May’s Brexit plan has his “full support.” “It’s a proposal that puts jobs first and protects our nation’s prosperity,” Hammond wrote.

The chaos engulfing May’s cabinet has raised questions about whether she could face a vote of no confidence from her own party. If she lost that vote, she would face a challenge for leadership of her party and could be forced to step down.

President Donald Trump will be visiting the UK on Thursday, and the subject of Brexit is bound to come up in talks with May. The world will be watching to see if he decides to try to make her life even harder in the likely event that he weighs in on the issue publicly.