A senior lawmaker of the main opposition Democratic Party (DP) said that suspension of President Yoon Suk Yeol from his duties is the only constitutional procedure and anything else is unconstitutional and an act of continuing treason.

Rep. Kim Min-seok, a member of the DP's Supreme Council, made the remarks on Sunday in a press conference at the National Assembly, soon after ruling People Power Party (PPP) Chairman Han Dong-hoon vowed to seek an "orderly retreat" of Yoon.

Kim voiced a clear opposition to the idea of an "orderly retreat," saying that even if President Yoon, Prime Minister Han Duck-soo, and the PPP chair reached an agreement among themselves, unconstitutional rule of the country cannot be allowed even for a minute.

The DP lawmaker then claimed that the prime minister cannot be a leading person in state administration under the Constitution and he is subject to an investigation in relation to Yoon's treason charges.

Kim said that the PPP chair is only a party leader with a fixed term and has also no constitutional or legal authority or actual political authority to lead state administration.

The lawmaker then called for the police investigation team to arrest and investigate all the figures involved in the martial law declaration, including Yoon.

Kim also called for depriving Yoon of his power to command the military, vowing to pass a special counsel probe over treason charges against the president and other officials.