British Foreign Secretary Boris Johnson resigned Monday, adding to divisions over Brexit that threaten to tear apart Prime Minister Theresa May’s government.

May’s office said in a terse statement that the prime minister had accepted Johnson’s resignation and would name a replacement soon.

Johnson, one of the best-known and most flamboyant members of the government, quit just hours after the resignation late Sunday of Brexit Secretary David Davis, the government’s top Brexit official.

Davis said he could not support May’s plan to maintain close trade and regulatory ties with the EU, which he said gave “too much away, too easily.”

There was no immediate statement from Johnson, another loud pro-Brexit voice within May’s divided government.

If Davis’s resignation rattled May, Johnson’s shook the foundations of her government.

The resignations came just days after May announced she had finally united her quarrelsome government behind her plan for a divorce deal with the EU.

Less than nine months remain until Britain leaves the bloc on March 29, 2019, and the EU has warned Britain repeatedly that time is running out to seal a divorce deal.

Britain and the EU hope to reach broad agreement by October so that EU national parliaments can ratify a deal before Britain leaves. That timetable looks increasingly optimistic, but European Commission spokesman Margaritis Schinas said the EU was available “available 24/7.”

Schinas said the bloc “will continue to negotiate in good will, bona fide, with Prime Minister Theresa May and the U.K. government negotiators in order to reach a deal.”