LONDON (AP) — Wes Streeting’s ambition to head the British government was one of the worst-kept secrets in U.K. politics.But if anyone was unaware, it’s now official — the former health secretary announced on Saturday his intention to oust Prime Minister Keir Starmer.“We need a proper contest with the best candidates on the field, and I’ll be standing,” Streeting said.Streeting is the first member of Parliament to say he will take on Starmer in what is likely to be a bruising internal contest for the reins of the Labour Party, which has seen its fortunes fall in the two years since its historic landslide victory swept out Conservatives after 14 years in power.Streeting is likely to face other challengers, including Greater Manchester Mayor Andy Burnham, if the latter can win a special election for a seat in the House of Commons that is expected to take place within the next few weeks.

Starmer has vowed to fight on despite being widely unpopular after a series of setbacks, policy U-turns and questions over his judgment for appointing a friend of the sex offender Jeffrey Epstein as U.S. ambassador. The government is facing weeks of chaos after he rejected calls to resign following the party’s disastrous results in the May 7 local and regional U.K. elections, in which Nigel Farage’s anti-immigrant Reform UK made huge gains.“The voters did more than send Labour a message last week,” Streeting said on Saturday. “They issued a warning: that unless we change course, we risk being the handmaidens of Nigel Farage and the breakup of the United Kingdom.”