Theresa May is set to resign as leader of the Conservative party on June 7, triggering a leadership contest that will decide the next U.K. prime minister.

The process for electing May's successor will begin the week after her resignation, and May will continue to serve as a caretaker prime minister until a successor is chosen, she said in a speech delivered outside No. 10 Downing Street, the official residence of the prime minister.

May has come under increasing pressure to step down in recent days after failing to find support for a fourth vote on her EU withdrawal agreement. Opinion polls show she is most likely to be replaced by Boris Johnson, who has repeatedly criticized the PM for her failure to deliver Brexit and has advocated for a cleaner break from the EU known as a "hard Brexit."

After talks to find a compromise with the opposition Labour party collapsed May 17, she added concessions to her Brexit deal, including the option of parliamentary votes on a second referendum and the possibility of closer trade ties with the EU.

May had previously planned to set out a timetable for her departure in June after a vote on the revised deal, but postponed publication following a backlash among Conservatives, while failing to attract Labour members of parliament. U.K. House of Commons leader Andrea Leadsom resigned from the government May 23.

May took office in 2016 following the referendum in which the U.K. decided to leave the EU, replacing David Cameron. She led the U.K. in Brexit negotiations with the EU, and reached a Withdrawal Agreement in November 2018, which was rejected by British lawmakers three times in Parliament, causing the U.K.'s departure from the bloc to be delayed to Oct. 31 from an initial deadline of March 29.

The pound was 0.3% stronger at $1.2700 at 6:07 a.m. ET.