South Korea's ruling party leader, Han Dong-hoon, on Friday called for President Yoon Suk Yeol to be removed from office, citing a "serious risk" of further attempts to impose martial law.

Yoon’s controversial declaration of martial law late Tuesday sparked outrage before lawmakers overturned the measure in a dramatic parliamentary showdown. Thousands of protesters rallied outside as Yoon was forced into a humiliating U-turn.

"Given the alarming new developments, I believe President Yoon's immediate suspension is crucial to protect the Republic of Korea and its citizens," said Han, head of the People Power Party. The statement marked a stark reversal from his earlier opposition to Yoon's impeachment.

Han warned that if Yoon remains in power, "there is a significant risk of similar extreme measures being taken again, jeopardizing the safety and stability of the nation."

Han added that "credible evidence" suggests Yoon ordered the arrest of "key politicians" to detain them in a holding facility.

Yoon "does not acknowledge that this illegal martial law is wrong" and has failed to act against military officials who "illegally intervened," Han said.

Impeachment vote

The opposition has already put forward a motion to impeach Yoon, with a vote scheduled for around 7 p.m. (10 a.m. GMT) Saturday. It had been unclear if the motion would pass.

Han’s comments, however, represent a stunning reversal a day after he said the PPP would block the motion, which requires a two-thirds majority to pass.

The opposition bloc holds 192 seats in the 300-member parliament, while the PPP has 108. A successful vote would suspend Yoon from office pending a ruling by the Constitutional Court.

"While there may still be a few ruling party members supporting Yoon Suk Yeol, Han’s statements today reflect the gravity of the situation, particularly the mobilization of intelligence agencies to arrest politicians," said Shin Yul, a political science professor at Myongji University.

"It appears Han and the party leaders have concluded there is a significant possibility that President Yoon may declare a second martial law," Shin said.

According to media reports, Han was set to meet the embattled president – who has not been seen publicly since the early hours of Wednesday – on Friday.

Lawmaker Jo Seung-lae, a spokesperson for the main opposition Democratic Party, told AFP that all party lawmakers would remain inside the National Assembly building until the impeachment vote on Saturday evening.

The decision was made in response to "a lot of tips the party has received" regarding a potential second attempt by Yoon to declare martial law, Jo said.

A new opinion poll released Friday showed support for the 63-year-old president, who has lurched from crisis to crisis since taking office in 2022, at a record low of 13%.

Investigation

Police said Friday that a 120-member team has been formed to investigate charges of insurrection filed by the opposition against Yoon and top officials.

"If evidence arises during the investigation suggesting preparations for a second martial law, we will pursue it," said Kim San-ho, an officer overseeing the investigation. Kim added there is currently no evidence of a second attempt.

On Thursday, Yoon’s office announced the resignation of Defense Minister Kim Yong-hyun. However, key allies, including Interior Minister Lee Sang-min, remain in office. Prosecutors have banned Kim from leaving the country, Yonhap news agency reported.

Lawmakers have grilled senior officials, including Army Chief of Staff Gen. Park An-su, who acted as Yoon’s martial law commander.

Park said Thursday he was unaware of the plan until after Yoon announced martial law on live television late Tuesday.

Opposition lawmaker Jo Seung-lae said Friday that security camera footage indicates soldiers attempted to arrest opposition leader Lee Jae-myung, National Assembly Speaker Woo Won-shik, and PPP chief Han.

The head of South Korean special forces, Kwak Jong-geun, said Friday he was ordered to "drag out" lawmakers from the parliament.

However, Yonhap quoted Yoon’s office denying that he ordered the arrests or detentions.

Seen on TV

In his late Tuesday address to the nation, Yoon claimed martial law was necessary to "safeguard a liberal South Korea from the threats posed by North Korea’s communist forces and eliminate anti-state elements plundering people’s freedom and happiness."

The announcement, which brought back painful memories of South Korea’s autocratic past, caught its allies off guard. The U.S. administration only learned of the declaration via television.

Media reports said U.S. Defense Secretary Lloyd Austin canceled a planned visit to South Korea – where nearly 30,000 U.S. troops are stationed – next week.

Security forces sealed the National Assembly, helicopters landed on the roof, and nearly 300 soldiers tried to lock down the building.

However, parliamentary staff blocked the soldiers with sofas and fire extinguishers. Enough lawmakers managed to get inside – many climbing walls to enter – to vote down Yoon’s measure.

"We cannot entrust the operation of the government to a president who threatens the lives of the sovereign people through unconstitutional and illegal actions, even for a moment," Democratic Party chief Lee Jae-myung said Friday.