South Korea’s Supreme Court faces an unusual vacancy for the first time in 30 years as the National Assembly motion to appoint a replacement for the retiring chief justice was delayed amid turmoil over an arrest warrant request for the main opposition party leader.

Ahn Chul-sang, the most senior of the 13 Supreme Court justices, will serve as acting chief justice starting Monday until the motion is considered and passed at the next Assembly plenary session.

In a meeting also held Monday, the Supreme Court will determine the scope of an acting chief justice's authority and decide if it is appropriate for the acting chief justice to have the same powers and duties as the head of the judiciary branch.

The motion to appoint the next Supreme Court chief justice was not voted on before the current one's retirement at the last plenary session on Sept. 21. During the same session, a motion to arrest Democratic Party of Korea leader Lee Jae-myung passed by a narrow margin, and the majority opposition party Assembly also voted to impeach Prime Minister Han Duk-soo.

The next Assembly plenary session won’t be until after the long weekend falling Sept. 28-Oct. 3 at the earliest. Even then it is unclear whether the motion to appoint the nominee -- Lee Gyun-yong, a senior judge at the Seoul High Court -- would pass, which would inevitably lead to an elongation of the vacancy period.

During the Assembly hearing, Democratic Party lawmakers called for the nominee's resignation, alleging he failed to report assets worth about 1 billion won ($750,000). Lee, reported to have a net worth of 7.2 billion won, is among the wealthiest justices nominated to lead the nation's highest court.

At the Assembly, the Democratic Party is still reeling from the passage of the motion allowing the court to decide on whether to issue an arrest warrant for its leader, who as a sitting lawmaker is protected from arrest without the majority consent of the Assembly. The party announced it was overhauling its floor leadership for failing to unite and strike the motion down.

According to prosecutors, Lee is accused of giving inside information and other favors to private developers in a city-led urban development project while he was the mayor of Seongnam, among other accusations.

The court is set to make a decision as to whether the accusations against Lee warrant arrest on Tuesday at the earliest.