STOCKHOLM—Swedish Prime Minister Stefan Lofven resigned on Monday, handing the speaker of its split parliament the task of finding a new government. Lofven had faced a deadline of midnight on Monday to either step down or call a snap election after losing a June 21 confidence vote when the Left Party withdrew its support. “I have requested to be dismissed as prime minister,” Lofven told a news conference, admitting defeat in his efforts to find fresh support from lawmakers that might have secured his reappointment. “It is the most difficult political decision I have ever taken.” Speaker Andreas Norlen will now have up to four attempts to find a new prime minister with enough backing from parliament. If he fails, a snap election must be called. Any new administration will be a short one, as regular polls must be held in September 2022. “With one year left until the election, …