U.K. Prime Minister Theresa May was plunged into the worst crisis of the past year after key members of the government quit over her Brexit plan. Her government is in disarray and her leadership in question just nine months before Britain leaves the European Union.

Brexit Secretary David Davis and his deputy, Steve Baker, resigned late on Sunday — just two days after May announced she had secured the backing of her whole Cabinet for a plan to keep close ties to the EU after leaving the bloc.

A replacement will be announced on Monday, May's office said, and the appointment will offer clues as to her tactics going forward.