The Yoon Suk Yeol administration's plan to restrict protests by groups with a record of allegedly illegal demonstrations as well as ban nighttime and rush-hour rallies, contradicts the Constitution as well as Yoon’s repeated emphasis on freedom and individual rights, critics said Thursday.

Political commentator Chin Jung-kwon called this plan "a ridiculous and unconstitutional idea" in an era where "violent protests" have ceased to exist, saying it is a thinly veiled attempt to clamp down on labor unions.

“Such a comment should not have been made by a president, and (Yoon's comment) had unconstitutional elements as well... (Yoon) always talks about 'freedom,' so I’m asking what this is,” Chin told a local radio Wednesday evening, referring to Yoon's public denunciation of an allegedly illegal protest by one of Korea's two main umbrella unions on Tuesday.

Chin's remarks echo opposition Democratic Party of Korea leader Lee Jae-myung's comments made Wednesday morning at a party meeting, saying that "Freedom of expression -- including freedom of assembly -- is a core fundamental right that underpins democracy."

“Any attempt to restrict such activity is an undermining of and attack on democracy,” he stressed.

The criticisms follow Yoon's open condemnation on Tuesday of the allegedly illegal protests by the labor group that he said disrupted people's lives.

"Seoul's transportation system was frozen because of the massive protest staged by the Korean Confederation of Trade Unions last week," Yoon said at a Cabinet meeting.

Saying a lack of supervision from the previous Moon Jae-in administration had resulted in protests harassing the people “to an unbearable level,” the conservative leader pledged not to “tolerate illegal acts.”

A day after Yoon’s comments, his ruling People Power Party came up with a proposal, which through a law revision would restrict protests by groups that have been found guilty of illegal activities in the past.

The party’s floor leader, Rep. Yun Jae-ok, said the revision would also ban protests conducted on roads during commuting hours and from midnight to 6 a.m.