SEOUL -- South Korea's main liberal opposition party said Tuesday it will wait until Thursday to introduce an impeachment motion against the country's acting president, according to the latest report by the Yonhap news agency.

The Democratic Party said earlier it would submit a motion on Tuesday to impeach Prime Minister Han Duck-soo, who became the acting president following the impeachment of President Yoon Suk-yeol.

The party floor leader Park Chan-dae said his party would immediately launch impeachment proceedings against Han, as the acting president had made it clear that he will not promulgate bills to appoint independent counsels and investigate insurrection charge for the impeached president and scandals involving his wife.

Earlier this month, the National Assembly passed a special counsel bill to investigate whether President Yoon committed insurrection and other violations over his declaration of martial law.

The parliament also passed a bill mandating a special counsel probe into two key allegations involving the first lady -- her alleged involvement in a stock manipulation scheme and interference in election nominations through a power broker.