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).

Last month, amid a series of mounting economic and political crises, South Korean President Yoon Suk Yeol issued a martial law decree—the first in more than 40 years. Yoon claimed that it was necessary to “eradicate anti-state forces” and “protect constitutional order.”