British Prime Minister Keir Starmer returns to the House of Commons after listening to the King's Speech during the State Opening of Parliament at the Palace of Westminster in London on Wednesday. | Pool / via REUTERS British Prime Minister Keir Starmer was struggling to hold on to power after his main rival in the government resigned on Thursday, accusing him of political drift, and others positioned themselves for potential challenges to his leadership. Disastrous results for the governing Labour Party in local elections last week have plunged Britain into a new crisis, just under two years after Starmer won a large majority on a vow to bring stability and ​end a decade of political chaos. After days of calls by Labour lawmakers for Starmer to quit or set out a timetable for his departure, Wes Streeting ‌resigned as health ‌minister, the first senior minister to break cover.…