Democratic Party nominee Lee Jae-myung will be retried on electoral violation charges, while the acting president has resigned and is expected to enter the race.

South Korea’s acting leader, Prime Minister Han Duck-soo, says he is resigning amid reports he will run in next month’s presidential election.

South Korea's top court cast doubt on Thursday on frontrunner Lee Jae-myung's eligibility to run for the presidency, while the resignations of the prime minister and finance minister shook the interim government in place since December's martial law.