Lawmakers attend a plenary session of the National Assembly in Seoul on Wednesday. (Yonhap)
Lawmakers attend a plenary session of the National Assembly in Seoul on Wednesday. (Yonhap)

The main opposition Democratic Party of Korea is set to propose a new bill on Thursday to appoint a special counsel to investigate President Yoon Suk Yeol on charges of insurrection, a day after its initial attempt to initiate further probes targeting the South Korean leader and his wife failed in a parliamentary vote.

The key difference in the newly devised bill concerns how the special counsels would be nominated. The previous version gave the right to nominate the special counsels to the main opposition Democratic Party and the minor opposition Rebuilding Korea Party, each of which would get to recommend one candidate.

But the new bill would purportedly relinquish the nominations to a neutral side.

Officials of the main opposition party have mentioned revising this specific clause of the earlier failed bill, but they have not yet specified which particular group would be entrusted with the nominations. The new version is also expected to undergo other changes, such as adjusting the scope of the investigation.

The Democratic Party plans to propose the bill later Thursday, and put it to a vote in a plenary session on Jan. 14 or 16.

The move comes a day after the main opposition's bid to launch a special probe into Yoon and his wife Kim Keon Hee was blocked by a nearly unanimous vote by the ruling People Power Party. Kim is suspected of stock price manipulation and interference in election nominations.

Of the 300 lawmakers present, 198 voted in favor of investigating Yoon and 196 for investigating Kim, both tallies just shy of the two-thirds approval required for them to pass. The two bills were put to a revote after Acting President Choi Sang-mok vetoed them late last month.

The ruling People Power Party has made it clear that its official position is to vote against the bills to investigate Yoon and Kim. Floor Leader Kweon Seong-dong on Wednesday said he suggested to Rep. Kim Sang-wook, a ruling party member who supported Yoon's impeachment last month and the proposed investigation, to leave the party if he would not comply.

"I told Kim, who acted against the party consensus, that it would be difficult (for us) to be in the same party if he is unable to agree with the consensus. I recommended that he seriously consider leaving the party," Kweon told reporters.

Kim said he has no intention of leaving the party.

"A lawmaker should carry out his duties in accordance with his conscience, prioritizing the interests of the nation. It would be wrong to apply pressure (by threatening expulsion). It is President Yoon who damaged the value of the conservatives the most, and he's the one who should be expelled from the party," he said.

The PPP has 108 seats in the opposition-controlled National Assembly, meaning just eight of its lawmakers breaking ranks would allow the special counsel probes into Yoon and Kim to pass.

Yoon is currently under criminal investigation and is undergoing impeachment proceedings in the Constitutional Court on charges of insurrection and abuse of power related to his Dec. 3 declaration of martial law and his allegedly illegal orders that followed.