South Korea's Constitutional Court dismissed the impeachment of Prime Minister Han Duck-soo, the latest development in the country's complex and sprawling political crisis
South Korea's Constitutional Court dismissed the impeachment of Prime Minister Han Duck-soo, the latest development in the country's complex and sprawling political crisis AFP

South Korea's Constitutional Court dismissed the impeachment of Prime Minister Han Duck-soo on Monday, reinstating him as acting president -- a role he took after the president was suspended for declaring martial law.

The court ruling is the latest development in South Korea's complex and sprawling political crisis, which President Yoon Suk Yeol started with a short-lived attempt to subvert civilian rule in December.

Lawmakers defied armed soldiers at parliament to vote down Yoon's December 3 martial law declaration and impeached him soon after, with Han stepping in as acting president.

But he was himself impeached by lawmakers just weeks later over his purported involvement in the martial law debacle, plus a dispute over judicial appointments.

"The Constitutional Court has rendered a decision to reject the impeachment trial request against Prime Minister Han Duck-soo," the court said Monday in a statement.

The court ruled 5 to 1 against Prime Minister Han's impeachment, with two judges arguing that the case should not have made it to court as lawmakers did not have a super majority to impeach Han in the first place.

Han's actions while in office "cannot be seen as constituting a betrayal of the people's trust indirectly granted through the President" the court rules.

The decision is effective immediately and cannot be appealed.

Han, who immediately resumed the acting presidency Monday, thanked the Constitutional Court for its "wise decision".

"I believe that all citizens are clearly speaking out against the highly polarised political sphere. I think there is no place for division now. Our country's priority is to move forward," he added.

The court's decision was closely watched as it comes ahead of a highly anticipated ruling on suspended President Yoon's impeachment, the date of which has not yet been announced.

Despite experts predicting a verdict on that case by mid-March, the Constitutional Court has yet to rule, making Yoon's case the longest deliberation in its history.

If Yoon's impeachment is upheld, South Korea must hold fresh elections within 60 days of the verdict.

Monday's ruling "does not have a direct legal correlation with the pending decision on Yoon's impeachment," Yoo Jung-hoon, attorney and political commentator told AFP.

"The judges did not deliberate on the legality of martial law but rather on Han's involvement in the case," he said.

Yoon was suspended by parliament in December.

He was arrested in January in a dawn raid in connection to a separate criminal investigation on insurrection charges -- which are not covered by presidential immunity.

He is the first sitting South Korean president to stand trial in a criminal case.

He was released from detention in early March on procedural grounds -- a move that has appeared to invigorate his supporters.

Hundreds of thousands of South Koreans took to the streets over the weekend, as rallies for and against Yoon intensified ahead of the court verdict.

Yoon's ruling People Power Party lawmaker Kweon Seong-dong told reporters at the National Assembly that Han's reinstatement was welcome.

The opposition who impeached him should "apologise to the people for paralysing state affairs for 87 days with a hasty impeachment bid," which was done for political purposes, Kweon added.

South Korea's presidential office welcomed Han's reinstatement.

"Today's decision reaffirms that excessive impeachments by the National Assembly are reckless and malicious political offensives," the office said in a press notice.

"We hope that acting President Han's return to duty marks the beginning of a return to normal governance."