SEOUL—South Korea’s legislature voted to impeach acting President Han Duck-soo on Friday after he declined to make judicial appointments needed to advance the impeachment of his predecessor, extending the political upheaval that began with a short-lived martial law declaration earlier this month.

The vote intensifies a political crisis as the Constitutional Court meets for its first hearing on suspended President Yoon Suk Yeol's short-lived martial law.

Han’s impeachment occurs amid weeks of political chaos following Yoon’s brief declaration of martial law on December 3, which lasted only six hours but led to widespread protests. This move intensified the political vacuum that has gripped South Korea.