A defiant South Korean President Yoon Suk Yeol faces a second impeachment vote on Saturday over his short-lived attempt to impose martial law, a move that shocked the country, split his party and imperilled his presidency half way through his term.

His move to impose military rule on Dec. 3 was rescinded barely six hours later after parliament defied troops and police to vote against the decree, but it plunged the country into a constitutional crisis and triggered widespread calls for him to step down for breaking the law.

Opposition parties plan to hold an impeachment vote at 4 p.m. (0700 GMT) on Saturday, with large demonstrations planned ahead of the vote.

Yoon’s conservative People Power Party boycotted the first impeachment vote a week earlier, preventing a quorum.

Since then, PPP leader Han Dong-hoon has urged party members to vote for impeachment on Saturday, and at least seven PPP members have said they would vote to impeach.

The opposition parties control 192 of the 300 seats in the single-chamber parliament so they need at least eight PPP votes to reach the two-thirds threshold for impeachment.

Ahn Cheol-soo, a PPP lawmaker among those backing Yoon’s impeachment, said in a Facebook post on Saturday that he would vote for impeachment “for the sake of swift stabilization of people’s livelihood, economy and diplomacy.”

The PPP floor leader said on Friday, however, that the party’s stance is still to oppose impeachment.

PPP lawmakers are due to meet on Saturday morning to decide whether to change that position.

If impeached, Yoon would lose authority but remain in office until the Constitutional Court either removes or reinstates him. In the meantime, Prime Minister Han Duck-soo would serve as acting president.

If the court removes Yoon or he resigns, a presidential election must be held within 60 days.

Yoon is separately under criminal investigation for alleged insurrection over the martial law declaration and authorities have banned him from travelling overseas.

He has not signalled a willingness to resign and in a speech on Thursday vowed he would “fight to the end” and defended the martial law decree as necessary to overcome political deadlock and protect the country from domestic politicians who are undermining democracy.

Yoon, president of Asia’s fourth-largest economy, hopes political allies will rally to support him, but the fiery remarks appeared to find mixed reception among PPP lawmakers.

A Gallup Korea poll on Friday had two-thirds of supporters of Yoon’s party opposing the impeachment, though three-quarters of all respondents supported it.

Elected in 2022, Yoon was widely welcomed in Washington and other Western capitals for his rhetoric defending global democracy and freedom, but critics said that masked growing problems at home.

He clashed with opposition lawmakers that he has labelled as “anti-state forces” and press freedom organisations have criticized his heavy-handed approach to media coverage that he deems negative.

The crisis and ensuing uncertainty shook financial markets and threatened to undermine South Korea’s reputation as a stable, democratic success story.

South Korean shares rose for a fourth straight session on Friday on hopes that the political uncertainty would ease after this weekend’s parliamentary impeachment vote.