South Korea's political turmoil deepened as the main opposition Democratic Party announced plans to impeach acting President Han Duck-soo. The move follows a heated dispute over unfulfilled appointments to the Constitutional Court, which is crucial in deciding the impeachment trial of President Yoon Suk Yeol.

The Democratic Party, which holds a parliamentary majority, said it would introduce the impeachment bill on Thursday and push for a vote on Friday.

Prime Minister Han, who has been serving as acting president since Yoon’s suspension, has faced mounting criticism for failing to appoint three justices to the Constitutional Court despite parliament’s approval of the nominees.

"It has become clear that Prime Minister and acting President Han Duck-soo does not have the qualification or the will to safeguard the Constitution," said Park Chan-dae, the Democratic Party’s floor leader, in a statement.

Han defended his decision to delay the appointments, citing the lack of political consensus. "Appointing justices without agreement among parties will harm constitutional order," he said on Thursday. The opposition argues that Han’s inaction has paralyzed the Constitutional Court, which needs six of its nine justices to rule on the impeachment case.

Of the three nominees approved by parliament, two were proposed by the Democratic Party and one by Han’s ruling People Power Party. However, the ruling party objected to the allocation, claiming no prior agreement had been reached.

If Han is impeached, Finance Minister Choo Kyung-ho would assume the acting presidency. However, legal experts are divided over whether a simple majority or a two-thirds vote is required to impeach the acting president.

The Constitutional Court is scheduled to begin hearings on Friday to determine whether President Yoon should be removed or reinstated. Yoon was impeached by parliament on December 14, following his controversial declaration of martial law on December 3.

Under the constitution, six of the nine Constitutional Court justices must agree to remove a president. With three vacancies on the bench, the remaining justices must vote unanimously to finalize Yoon’s removal.

Adding to the tensions, Yoon has refused to submit legal documents to the court and ignored a summons for questioning in a separate criminal investigation. His defiance has prompted the opposition to call for his arrest.

As the crisis escalates, South Korea finds itself at a critical juncture, with constitutional order and political stability hanging in the balance.