South Korea’s liberal-led legislature has voted overwhelmingly to launch special investigations into former President Yoon Suk Yeol’s short-lived imposition of martial law in December and criminal allegations against his wife.

Pre-election surveys suggest Yoon Suk Yeol's liberal rival, Lee Jae-myung, appears headed for an easy win, riding a wave of public frustration in the wake of Yoon's martial law debacle.

The new president, who will take office immediately, faces a number of pressing challenges including repairing domestic divisions, navigating US trade tensions and confronting North Korea’s growing nuclear threat.