A second motion submitted by the largest opposition party in South Korea to impeach President Yoon Suk Yeol secured the required two-thirds majority in the country’s parliament on Saturday.
Their first motion a week ago failed after members of Yoon’s ruling People Power Party (PPP) boycotted the proceedings, leaving it without a quorum.
Of the 300 members, 204 voted in favour of launching impeachment proceedings.
Prime Minister Han Duck Soo is to assume presidential duties until the Constitutional Court takes the final decision on whether to confirm Yoon’s impeachment or declare it unconstitutional.
The opposition has accused Yoon of violating the constitution after his unexpected declaration of martial law on December 3.
The move shocked the nation but was rescinded just hours later following massive public resistance.
Despite freezing temperatures, some 200,000 demonstrators had gathered outside the parliament building on Saturday to support Yoon’s impeachment.
Police estimate that a further 30,000 of his supporters gathered in the centre of the capital, Seoul.
During the first impeachment vote on December 7, Yoon, of the ruling People Power Party (PPP), benefited from a change of mind from PPP leader Han Dong Hoon, who first said he would back the impeachment but then backtracked.
But on Thursday Han openly declared his support for ousting Yoon, who has remained stubbornly defiant in defending his short-lived martial law declaration.
Yoon, in a televised address on Thursday, labelled his political opponents “anti-state forces.”
The Constitutional Court now has a maximum of 180 days to make a final decision on Yoon’s impeachment.