South Korea’s National Assembly voted to impeach acting president Han Duck-soo on December 27, 2024, less than two weeks after lawmakers suspended President Yoon Suk Yeol. The unprecedented removal of an acting president intensified a constitutional crisis that began with Yoon’s short-lived attempt to impose martial law.
A total of 192 lawmakers supported the motion against Han, comfortably exceeding the 151-vote threshold announced by National Assembly Speaker Woo Won-shik. Members of the governing People Power Party disputed that threshold, arguing that the 200 votes required to impeach a president should also apply to an acting president. Many of its lawmakers boycotted the ballot after protesting in the chamber and calling the vote invalid.
Han, who remained prime minister while taking over presidential duties, became the first acting president impeached since South Korea’s democratic transition. He said he respected the Assembly’s decision and would suspend his duties rather than add to the turmoil while awaiting a ruling from the Constitutional Court. Finance Minister Choi Sang-mok was set to assume the responsibilities of both acting president and acting prime minister.
The immediate dispute concerned three nominees for the Constitutional Court. Opposition lawmakers accused Han of obstructing Yoon’s impeachment process by declining to appoint judges selected by parliament. The court ordinarily has nine members but was operating with six. At least six judges were required to uphold Yoon’s removal, meaning one opposing vote on the smaller bench could defeat the impeachment. The opposition wanted the vacancies filled before the court considered Yoon’s case.
Han’s own impeachment must also be reviewed by the Constitutional Court, which has up to 180 days to decide whether to uphold it. The overlapping proceedings placed the court at the centre of the country’s political future while the executive branch passed to a third officeholder within weeks.
The crisis began on December 3, when Yoon declared martial law and cited a need to protect the country from what he called anti-state forces. Lawmakers overcame barriers around parliament and voted 190-0 to reject the measure. Yoon withdrew it hours later, subsequently apologising while defending his stated motive. Parliament then impeached him, and investigations expanded into the actions of senior officials.
Financial markets reflected the uncertainty. On the day of Han’s impeachment, the won fell to its weakest level against the US dollar since the global financial crisis 16 years earlier. Each major party blamed the other for the instability, while the country entered another phase of institutional uncertainty without a final decision on either impeachment. The transfer to Choi kept executive functions operating, but did not settle the underlying constitutional conflict.
