Two separate motions seeking the arrest of opposition leader Lee Jae-myung and the dismissal of Prime Minister Han Duck-soo were submitted during the parliament's plenary session on Wednesday.
The motions will be put to an anonymous vote during a plenary session Thursday.
According to the National Assembly Act, lawmakers are mandated to vote on such motions within 72 hours of their submission to the parliamentary plenary session. The vote can begin 24 hours after the submission.
The motion requesting parliamentary consent to lift the arrest immunity of Lee of the main opposition Democratic Party (DP) was reported following President Yoon Suk Yeol's approval a day earlier.
By law, sitting lawmakers are immune from arrest while parliament is in session and can be arrested only when the National Assembly consents to it. But the privilege came under criticism that it is abused to protect corrupt politicians.
Lee has been accused of breach of trust, bribery and other charges in connection with a scandal-ridden land development project and involvement in a company's illegal cash remittance to North Korea.
The motion, however, can be rejected if DP lawmakers vote against it, as the party holds a majority with 167 seats in the 297-member parliament. The vote is expected to be cast by 295 lawmakers, excluding Lee, who has been hospitalized, and an independent lawmaker under detention.
Later in the day, the DP convened a lawmakers' meeting and decided not to establish a party line on the motion but leave its members to vote on their own.
"We listened to various opinions, so each lawmaker will ponder and make a judgment accordingly," a party spokesperson said after the meeting.
"The Supreme Council considered it appropriate to reject the arrest motion without a party line and asked lawmakers to make a decision considering this," she added.
Lee, who has been on a hunger strike for nearly three weeks in protest against government policies, urged the motion against him to be dismissed.
"Approving this clearly illegal and unfair arrest motion will only serve to fuel the political prosecution's fabricated investigation," Lee said in a Facebook message.
In February, the prosecution's attempt to detain Lee on allegations of corruption in two separate corruption cases fell through after the parliamentary disapproval.
The DP has strongly condemned the Yoon government and the prosecution for seeking the warrant when the regular National Assembly session is under way, even though Lee declared he would cooperate. Lee had stated he would waive his privilege and consent to the warrant during a non-session period.
Separately, the DP submitted the motion seeking Han's dismissal to the parliament on Monday, accusing him of serious incompetence as chief of the Cabinet and holding him responsible for what it called the Yoon administration's failures in areas including the response to Japan's release of radioactive water from the Fukushima nuclear power plant and the mismanagement of last month's World Scout Jamboree.
However, Yoon is expected to reject the motion, despite its highly likely passage on Thursday.
The DP has passed two dismissal motions since the launch of the Yoon administration -- one against Foreign Minister Park Jin and another against Interior Minister Lee Sang-min. Both were rejected by the president.
The presidential office sees the DP's move against Han as a political offensive aimed at diverting public attention and boosting party unity ahead of an upcoming parliamentary vote on whether to allow the arrest of Lee.
Source: Yonhap News Agency