South Korea's main opposition party introduced a bill to impeach acting President Han Duck-soo on Thursday, a day before it plans to seek a vote on the move, which could deepen a constitutional crisis triggered by a short-lived martial law.

South Korea's opposition lawmakers have filed a motion to impeach the country's prime minister and acting leader Han Duck-soo, less than two weeks after parliament voted to impeach President Yoon Suk Yeol. This comes after Han refused to appoint constitutional court judges nominated by the main opposition Democratic Party (DP).

South Korea’s main opposition party said Tuesday it will seek to impeach acting leader Han Duck-soo after he missed an opposition-set deadline to approve independent investigations into impeached President Yoon Suk Yeol and his wife.

Prime Minister Han Duck-soo, who became South Korea's acting president after Yoon Suk Yeol's impeachment, is a career technocrat whose wide-ranging experience and reputation for rationality may not be enough to stem the country's deepening political crisis.

South Korea’s main opposition party has submitted a motion to impeach the country’s acting leader over his reluctance to fill three Constitutional Court vacancies ahead of the court’s review of rebellion charges against impeached President Yoon Suk Yeol stemming from his short-lived martial law decree on Dec.