South Korea's opposition leader warns of another martial law attempt

South Korea's main opposition leader Lee Jae-myung warned that President Yoon Suk Yeol might make another attempt to declare martial law before parliament votes on impeaching him on Saturday.

Yoon's brief imposition of martial law late on Tuesday sent Asia's fourth-largest economy into turmoil, with Lee's Democratic Party and other minor parties pushing to pass an impeachment motion against Yoon as early as Saturday afternoon.

As Lee was preparing for an interview with Reuters at his office within the National Assembly building on Friday afternoon, rumours spread that Yoon might visit the parliament, prompting opposition lawmakers to scramble to gather to block him, fearing another attempt at martial law.

Yoon's office said he was not planning to visit and the acting defence minister said reports about a possible second martial law order were untrue.

But Lee said there was still a possibility of another spontaneous late-night declaration to try to turn around the situation, though he did not offer substantive evidence.

"The situation is getting worse, there are fewer ways to escape, and he might see it as a breakthrough to destroy the existing systems and create a situation where he can do whatever with his power, however unreasonable that might be," Lee said.

"That's why it's very dangerous tonight, because the only chance he has is tonight and tomorrow morning."

Impeachment vote

The impeachment requires support from two-thirds of the 300-member assembly to pass, which means at least eight of the 108 legislators from Yoon's ruling People Power Party (PPP) must vote for it.

The conservative PPP has said it would block Yoon's impeachment, a formal position it reaffirmed late on Friday after a lengthy meeting of its lawmakers.

That came even though its chief, Han Dong-hoon, had earlier said that Yoon needed to be removed from power.

Lee said Han's view might not represent the official party line, but the likelihood for passing the motion was increasing.

"Even if he may avoid it tomorrow, the conclusion will eventually come down to one thing whether it be the day after tomorrow, a week later or a month later - the only way to tackle the situation is to impeach him unless he resigns," he said.

If parliament votes to impeach, the president is suspended from duty until the Constitutional Court decides whether to oust him. The prime minister serves in an acting capacity until a snap election is held.

Lee, who narrowly lost to Yoon in the 2022 presidential election, is seen as a top contender if Yoon is removed and a snap election is held.

A criminal conviction in November for an election law violation and further pending criminal cases may jeopardise his standing to run, however, and many members of Yoon's party have cited the need to stop Lee as a reason to oppose impeachment.

When asked if he would run, Lee said now was not the time to think about it, but to gather all strength to overcome the crisis as soon as possible before economic and diplomatic repercussions become serious.

"The current situation is not from a problem rooted in our country or democracy, but it's like a virus that happened to infiltrate into our perfectly functioning system," he said.

"So we have to focus on removing the virus. With proper, rapid treatment, we will recover, and through the process, our nation and democracy will become even stronger."