SEOUL, South Korea (AFP)— South Korean President Yoon Suk Yeol escaped impeachment Saturday over his brief declaration of martial law, after lawmakers from his ruling party boycotted a vote despite huge protests outside parliament.

Yoon stunned the nation and the international community on Tuesday night by suspending civilian rule and sending troops to parliament, but was forced into a U-turn after lawmakers nixed his decree.

Opposition parties proposed the impeachment motion, which needed a two thirds majority to pass, but a near-total boycott by Yoon’s People Power Party (PPP) doomed it to failure.

“The number of members who voted did not reach the required two-thirds majority,” National Assembly speaker Woo Won-shik said, saying that as a result, the impeachment vote was “not valid”.

The country — and the world — was watching, he said, adding it was “very regrettable that a vote could not even be held on such a significant national issue”.

He said it signified “a failure to engage in the democratic process” on the part of the ruling party.

The PPP claimed after the vote that it had blocked the impeachment to avoid “severe division and chaos”, adding that it would “resolve this crisis in a more orderly and responsible manner”.

The outcome disappointed the huge crowds — numbering 150,000 according to police, one million according to organisers — demonstrating outside parliament for Yoon’s ouster.

Demonstrators booed while some sighed or even wept in frustration as the ruling party lawmakers walked out of the chamber.

“Even though we didn’t get the outcome we wanted today, I am neither discouraged nor disappointed because we will get it eventually,” said Jo Ah-gyeong, 30.

“I’ll keep coming here until we get it,” she told AFP.

The opposition has already vowed to try again as soon as Wednesday, and many protesters vowed to continue demonstrations next weekend.

“I will impeach Yoon Suk Yeol, who has become the worst risk for South Korea, at any cost,” opposition leader Lee Jae-myung said.

Before the vote, Yoon, 63, apologised for the turmoil but said he would leave it to his party to decide his fate.

“I caused anxiety and inconvenience to the public. I sincerely apologise,” he said in the televised address, his first public appearance in three days.

He said he would “entrust the party with measures to stabilise the political situation, including my term in office”.

The backing of PPP lawmakers came despite party head Han Dong-hoon — who was allegedly on an arrest list on Tuesday night — saying Yoon must go.

Only three PPP lawmakers — Ahn Cheol-soo, Kim Yea-ji and Kim Sang-wook — voted in the end.

The failure of the impeachment motion “means a more protracted political crisis,” Vladimir Tikhonov, professor of Korean Studies at the University of Oslo, told AFP.

“We will have a politically dead president — basically unable to govern any longer — and hundreds of thousands coming to the streets every week until Yoon is removed,” he said.

Had the motion passed, Yoon would have been suspended from duties pending a ruling by the Constitutional Court.

An opinion poll released Friday put backing for the president at a record low of 13 per cent.