A National Assembly committee approved a motion that would mandate the appointment of a permanent special counsel to investigate whether President Yoon Suk Yeol committed insurrection by issuing his short-lived martial law decree on Dec. 3. The approval allows the proposal to be put to a parliamentary vote scheduled Tuesday.

The motion was introduced Friday by the main opposition Democratic Party of Korea.

All eleven opposition lawmakers on the parliamentary Legislation and Judiciary Committee voted to advance the motion, while seven ruling party lawmakers boycotted the vote.

As the motion only requires a simple majority, observers say it is likely to pass in Tuesday's plenary vote. The opposition coalition, which holds a 192-seat majority in the 300-seat Assembly, has the power to pass most bills without ruling party support.

Yoon and several of his current and former aides, including Prime Minister Han Duck-soo, ruling People Power Party Rep. Choo Kyung-ho and former Defense Minister Kim Yong-hyun, would be subject to the permanent counsel probe, accused of insurrection or collusion in the act of insurrection.

Unlike a regular special counsel investigation, which is initiated by the Assembly passing a specific law for the purpose, the appointment of a permanent special counsel involves the activation of an existing law -- the Act on the Appointment of an Independent Prosecutor. This strips the president of his power to veto the appointment of a permanent special counsel.

However, the president retains the power to confirm and appoint as special counsel one of two candidates proposed by a seven-member committee of legal experts. He must do so within three days, but the law does not specify a punishment for the president if he fails to meet the deadline.

The law also states that the investigation must be completed within 110 days, unlike a regular special counsel, who can be given more flexibility by stating the deadline in the initial appointment bill.

The main opposition on Monday also introduced two separate bills calling for regular special counsel investigations into insurrection charges against Yoon and allegations that first lady Kim Keon Hee was involved in a stock manipulation scandal that unfolded nearly a decade ago. This marks the fourth time the Democratic Party has floated a special counsel bill targeting the first lady. The previous three versions of the bill were scrapped due to a lack of quorum for revotes in the Assembly after Yoon vetoed all three of them.

The Democratic Party's motion to appoint a permanent special counsel comes as momentum builds for multiple law enforcement investigations against the president on charges of insurrection. Since Yoon's martial law decree on Dec. 3, which lasted six hours before it was lifted, the prosecution, police and the Corruption Investigation Office for High-ranking Officials have launched separate investigations into the case.

In addition to the motion to appoint a permanent special counsel, the main opposition, early in the day, said that it plans to put forward a bill to downsize next year's government budget during Tuesday's plenary session. The bill aims to slash next year's budget to 677.4 trillion won ($485.3 billion), which is 4.1 trillion won less than the budget proposed by the government. Cabinet members have pointed out that the Democratic Party's downsized budget would present significant hurdles to the Yoon administration's initiatives.

The Democratic Party, the previous day, said it would cut an additional 700 billion won from the 677.4 trillion won, to reduce the salaries of presidential officials. On Monday, the party stressed that there would be "no negotiations on the budget without Yoon's impeachment."

The main opposition said Monday it sought to file a complaint with the CIO against Prime Minister Han Duck-soo, accusing him of insurrection.

Meanwhile, the opposition plans to introduce a second impeachment motion against Yoon on Saturday. The first motion to impeach Yoon was scrapped on Dec. 7 after failing to meet the quorum of 200 votes in the 300-member Assembly.