Seoul (AFP) - South Korean lawmakers kickstarted a push to impeach President Yoon Suk Yeol in the early hours of Thursday, accusing him of declaring martial law to stop criminal investigations into himself and his family.

Yoon’s declaration of South Korea’s first martial law in more than four decades was swiftly overturned by lawmakers in a night of drama, but has plunged the country into political turmoil and alarmed its close allies.

The future of Yoon, a conservative politician and former star public prosecutor who was elected president in 2022, now looks highly uncertain.

After jumping fences and tussling with security forces to get into parliament and vote down the martial law overnight, opposition lawmakers filed a motion to impeach Yoon.

The motion says Yoon “gravely and extensively violated the constitution and the law” and accuses him of imposing martial law “with the unconstitutional and illegal intent to evade imminent investigations… into alleged illegal acts involving himself and his family”.

In an early Thursday morning session, lawmakers presented the impeachment motion to parliament.

“This is an unforgivable crime – one that cannot, should not, and will not be pardoned,” MP Kim Seung-won said.

- ‘Tragic’ -

Under South Korean law, the motion must be voted on between 24 and 72 hours after it is presented to a parliamentary session, according to Yonhap news agency.

Yoon’s prospects look bleak – the opposition holds a large majority in the 300-member legislature and needs only a handful of defections from the president’s party to secure the two-thirds majority needed to pass the motion.

The main opposition Democratic Party has also filed a complaint of “insurrection” against the president, some of his ministers and top military and police officials – which can carry a penalty of life imprisonment or even death.

In a show of public anger with Yoon, thousands of protesters converged around his office in central Seoul late Wednesday after staging a rally in Gwanghwamun Square, demanding his resignation.

Seoul’s stock exchange closed down more than one percent Wednesday as markets were roiled by the turmoil.

Even the leader of Yoon’s own ruling party described the martial law attempt as “tragic” while calling for those involved to be held accountable.

But party lawmakers then decided to oppose the motion to impeach Yoon, Yonhap reported early Thursday.

- Lawmakers defiant -

In his late-night television announcement imposing martial law on Tuesday, Yoon cited the threat of North Korea and “anti-state forces”.

More than 280 troops, some flown in by helicopters, arrived at parliament to lock down the site.

But 190 lawmakers defied rifle-carrying soldiers to force their way into the building to vote against the move.

The constitution says martial law must be lifted when a parliamentary majority demands it, leaving Yoon with little choice but to retract his decision and call off the military in another televised address six hours later.

Senior aides to Yoon offered to resign en masse Wednesday, as did the defence minister, who said he took “full responsibility for the confusion and concern” around the martial law declaration.

By evening, Yoon had yet to publicly reappear.

The repeal of martial law prompted jubilation among flag-waving protesters outside parliament who had braved freezing temperatures to keep vigil through the night in defiance of Yoon’s order.

Demonstrator Lim Myeong-pan, 55, said Yoon must now go.

“Yoon’s act of imposing it in the first place without legitimate cause is a serious crime in itself,” Lim told AFP.

“He has paved his own path to impeachment with this.”

As night fell in Seoul, protesters gathered again, ramping up their calls for Yoon to go.

“I was so incensed I couldn’t sleep a wink last night, I came out to make sure we push out Yoon once and for all,” 50-year-old Kim Min-ho told AFP.

- ‘Anti-state’ elements -

Yoon said martial law was needed to “safeguard a liberal South Korea from the threats posed by North Korea’s communist forces and to eliminate anti-state elements plundering people’s freedom and happiness”.

Yoon did not elaborate on the North’s threats, but the South remains technically at war with nuclear-armed Pyongyang.

The president labelled the Democratic Party “anti-state forces intent on overthrowing the regime”.

In recent weeks, Yoon and his People Power Party have been bitterly at odds with the opposition over next year’s budget.

His approval rating dropped to 19 percent in the latest Gallup poll last week, with voters angry at the state of the economy as well as controversies involving his wife, Kim Keon Hee.

Yoon’s action took allies by surprise, with the United States, which has nearly 30,000 troops in the country, saying it had no prior notice and voicing relief at his reversal.

“The ROK is demonstrating democratic resilience,” US National Security Council spokesman Sean Savett wrote on X, expressing confidence that the situation would be resolved “peacefully, democratically and constitutionally”.