Han Dong-hoon says ‘credible evidence’ shows president intended to arrest political leaders.

The head of South Korea’s ruling party has called for the swift suspension of President Yoon Suk-yeol’s powers, citing “credible evidence” that he sought the arrest of political leaders following his short-lived declaration of martial law.

People Power Party (PPP) leader Han Dong-hoon, who had earlier said he would oppose efforts to impeach Yoon, said “newly emerging facts” had tipped the scales against the president.

“I learned last night the president ordered the defence counter-intelligence commander to arrest major political leaders, characterising them as antistate forces, and mobilised intelligence institutions in the process,” Han said.

“I have said that to prevent this country from descending into further chaos, I would try to stop the impeachment bill from passing this time,” Han added.

“But based on what has been revealed, to protect South Korea and our people, I believe it is necessary to stop President Yoon from exercising his powers as president promptly.”

Han said that Yoon had failed to acknowledge that his martial law declaration was illegal and wrong, and there was a “significant risk” that he could take similar extreme action again if he stayed in office.

South Korea was placed under martial law for about six hours on Tuesday night after Yoon announced the move in a surprise televised address to the nation in which he cited threats from “anti-state forces” and North Korean sympathisers.

The National Assembly quickly mobilised to overturn Yoon’s order in a 190-0 vote.

Yoon lifted the order at about 4am, but not before troops had descended on the National Assembly and scuffled with legislators and protesters.

As well as facing impeachment, Yoon is currently under investigation for treason alongside resigned Defence Minister Kim Yong-hyun, Army Chief of Staff General Park An-su and Interior Minister Lee Sang-min, according to local media reports.

The call from Han, who is the justice minister and one of Yoon’s top rivals in the PPP, marks a decisive shift in the ruling party’s response to the crisis.

The opposition Democratic Party has called for a vote on Saturday night to impeach Yoon, but it needs at least eight votes from the ruling party to reach the necessary two-thirds threshold in the 300-member National Assembly.

If the motion is successful, South Korea’s Constitutional Court would then rule on whether to confirm Yoon’s removal from office.

Until now, the PPP had indicated it would oppose Yoon’s impeachment, with some analysts suggesting that lawmakers feared backlash for going against their own party, as occurred following the impeachment of former President Park Geun-hye in 2016.

Park was later sentenced to 20 years in prison for corruption before she was pardoned.

Not including Yoon, four of South Korea’s seven presidents have either been impeached or jailed for corruption since the country’s transition to democracy in the late 1980s.