Opposition leader Rep. Lee Jae-myung expressed disappointment Saturday over President Yoon Suk Yeol's televised apology at 10 a.m. the same day, in which he said he would entrust power to his party.

"I was extremely disappointed," said Lee, who leads the main opposition Democratic Party of Korea, adding Yoon's address "did not meet the expectation of the ordinary people at all, and was rather feeding ordinary people's anger."

He also said the existence of the incumbent president poses the biggest threat to the country, pressing a need for Yoon to step down immediately.

Lee later elaborated that Yoon's martial law declaration was proof that his administration dares to "act aggressively on an impulse in a way that ordinary people cannot imagine."

Rep. Park Chan-dae, floor leader of the Democratic Party, said the party would float impeachment motions indefinitely starting Wednesday, when the extraordinary session of the 22nd National Assembly kicks off. This will allow the party, which holds a majority at the parliament, to repeatedly "knock the door until it opens," Park said.

Democratic Party lawmakers also blasted Yoon's announcement that he would entrust his power to the ruling party to stabilize state affairs. They accused him of trying to take shelter in his party without bearing any legal responsibility for his martial law declaration.

Lee claimed that the ruling party would inevitably be dissolved, should any evidence of its involvement in troops' forcible entry into the National Assembly materialize.

People Power Party floor leader Rep. Choo Kyung-ho "might have played a role of impeding the National Assembly's resolution to nullify martial law," Lee suspected, describing the party as a possible "perpetrator of the insurrection."

Rep. Kim Min-seok of the main opposition party, a four-term lawmaker, said he did not trust Yoon's assurances that he would not declare martial law again, "as long as Yoon remains on top of the military chain of command in South Korea."

"There is no other option left than Yoon's immediate resignation from his post or impeachment that would force Yoon to step down," Lee said.

Yoon's term is scheduled to end in May 2027, but he would be forced to end his five-year term prematurely if he is impeached. The impeachment motion is to be put to a vote later on Saturday at 5 p.m., according to the main opposition party.