London — British Prime Minister Keir Starmer announced Monday that he was resigning from his position as the leader of the ruling Labour Party, which will also see him replaced as the country’s leader. Starmer has been under mounting pressure to resign for weeks, and his decision came after a political rival from within Labour, former Manchester Mayor Andy Burnham, made it clear that he would challenge the prime minister for his job. Starmer had vowed to stay in his post, but his position became untenable as more and more Labour Party colleagues concluded his time was up. The timetable for his departure sped up after Burnham left his role as mayor and then won a seat last week as a Member of Parliament for his local constituency — a necessary move as prime