South Korea's main opposition party head, Lee Jae-myung, said Wednesday he was stepping down as party leader, amid expectations that the current populist front-runner for the presidency in opinion polls would soon declare his run.

South Korea's labor minister, Kim Moon-soo, who has been among ruling People Power Party (PPP) members indicating an intention to run, also declared his candidacy.

South Korea will hold a snap presidential election on June 3, after former president Yoon Suk Yeol's impeachment stemming from a December martial law declaration was upheld.