Opposition leader Lee Jae-myung is on course to be South Korea’s next president following a snap election, with official results showing him well ahead of his main rival who conceded defeat early Wednesday morning.

South Korea's voters cast their ballots in a snap presidential election sparked by the impeachment of Yoon Suk Yeol.

Both Lee and conservative Kim pledged change for a country deeply scarred by a shock martial law briefly imposed by former leader Yoon Suk Yeol.