A TV screen at the Seoul Station shows President Yoon Suk Yeol's declaration of martial law the previous night, Dec. 4. Yonhap

President Yoon Suk Yeol has come under growing attacks from the main opposition party to face impeachment or charges of treason, in the wake of his short-lived attempt to impose martial law that was blocked by the National Assembly.

In a surprise move, Yoon declared "emergency" martial law Tuesday night, accusing opposition parties of disrupting the country's functions by pushing to impeach government officials and cut next year's budget.

Yoon's brief declaration of martial law, however, shocked the nation as martial law troops stormed into the National Assembly compound, as such martial law was the first since Korea introduced the current democratic system in 1987.

The declaration was lifted around early Wednesday, after the National Assembly overwhelmingly rejected it in a 190-0 vote, with some lawmakers from the ruling People Power party (PPP) joining the opposition. The martial law decree was effective only about six hours.

Yoon's rash action threw Korea into political chaos and put his own political fate in jeopardy as opposition lawmakers openly called for his removal from office.

The main opposition Democratic Party of Korea (DPK) said it will file treason charges against Yoon as well as his defense and interior ministers and impeach them to hold them accountable for the action.

Following Yoon's late-night TV announcement, around 280 martial law troops broke into the National Assembly and police officers blocked its entrance, according to the parliament's secretary-general.

DPK leader Lee Jae-myung called the martial law declaration "illegal," asserting Yoon is "no longer the president" of Korea.

The parliament must vote on whether to proceed with impeachment within 72 hours after the motion is reported to the plenary session, which would require a two-thirds majority in the 300-member parliament to pass.

The DPK and other small opposition parties together have 192 seats, which means at least eight out of 108 PPP lawmakers need to support the impeachment for it to pass.

If successful, the Constitutional Court would then rule on whether Yoon's removal from office is warranted.

During the court's deliberation, the president's constitutional powers would be suspended, and Prime Minister Han Duck-soo, as the No. 2 official in the government, would assume presidential responsibilities.

While some PPP lawmakers voted against Yoon's martial law declaration, it remains uncertain whether they would side with opposition parties in supporting his impeachment.

People Power Party leader Han Dong-hoon arrives at the National Assembly in Seoul to attend an urgent meeting, Dec. 4. Yonhap

Han Dong-hoon, chief of the ruling People Power Party (PPP), said PPP lawmakers largely agreed on dissolving the Cabinet and dismissing the defense chief but were divided over whether to call on Yoon to leave the party.

Yoon, elected in May 2022 by a narrow margin against DP leader Lee, has faced consistent challenges from opposition parties and internal divisions within his conservative party, partly fueled by controversies involving first lady Kim Keon Hee.

His abrupt martial law declaration triggered political turmoil and alarmed international allies, including the United States, which welcomed Yoon's revoking the martial law decree.

Secretary of State Antony Blinken said the U.S. continues to expect "political disagreements to be resolved peacefully and in accordance with the rule of law."

Concerns are mounting over potential leadership gaps at a time of growing security and economic challenges expected from former U.S. President Donald Trump's return to the White House next month. Yoon had planned to meet Trump as soon as after his inauguration on Jan. 20.

Adding to the tension, the DP also plans to hold a revote next week on a special counsel bill targeting the first lady's corruption and election interference allegations.

The bill, vetoed by Yoon for the third time, requires a two-thirds majority to override the veto. (Yonhap)