U.K. Prime Minister Keir Starmer is expected to set out a timetable for his departure on Monday, reports suggest, kickstarting a process that will see the country appoint its seventh leader in a decade. Andy Burnham, Labour's former Greater Manchester Mayor, is favorite to replace Starmer after winning a special election in north-west England last week that will see him return to parliament. Following that result, Starmer had initially vowed to fight any leadership challenge. However, speculation that Starmer may now quit mounted over the weekend. A number of senior U.K. government ministers have reportedly urged the prime minister to spell out an exit plan, including Foreign Secretary Yvette Cooper, Home Secretary Shabana Mahmood and Energy Minister Ed Miliband.watch nowA heavy defeat in last month's local elections, coupled with sustained poor opinion polling, has steadily eroded the prime minister's authority over the ruling Labour Party.Starmer's resignation would clear the way for Burnham — due to be sworn in as a member of parliament later Monday — to succeed him as Labour leader and U.K. prime minister.Burnham's sizable victory in last week's Makerfield by-election has further bolstered his standing within the party, making a leadership contest unlikely and leaving him poised to enter Downing Street unopposed.U.S. President Donald Trump said in a TruthSocial post on Sunday that Starmer will resign."He failed badly on two very important subjects- IMMIGRATION AND ENERGY (OPEN NORTH SEA OIL!)," Trump said in the post.