The Yoon Suk Yeol administration and the ruling People Power Party are mulling steps to restrict groups with a criminal background from staging protests, in an apparent aim at a labor union at the center of a spiraling North Korea spying scandal.

At a policy meeting Wednesday, Cabinet officials and party leaders agreed to push an amendment to existing laws to curb criminally involved groups’ abilities to hold assemblies and demonstrations.

The latest move follows the indictment of several former and current leaders at the Korean Confederation of Trade Unions, the country’s main umbrella labor union. Seoul prosecutors believe the union officials have been working with a North Korean spy agency with an anti-government agenda.

In an indictment released last week, prosecutors wrote that the union officials arrested earlier this month have been communicating with North Korean spies over several years, at times meeting with them in person in Southeast Asian countries such as Vietnam.

According to prosecutors, the union officials referred to the spy agency for the Workers Party as “headquarters” and Kim Jong-un as “president” and the “supreme leader” in their communications with North Korea. The union officials and North Korean spies called one another “brothers” and “comrades.” The officials called their own union the “sales team” in a code word.

The ruling party head Rep. Kim Gi-hyeon said the indictment suggested the union was “more invested in working for North Korea than representing the interests of workers here.”

Rep. Yun Jae-ok, the ruling party’s floor leader, told reporters following Wednesday’s policy meeting that the proposed amendment would “not bar protests altogether.”

“That is not the intention at all,” he said, explaining that the amendment sought to limit assemblies or demonstrations “organized by groups with a criminal orientation threatening public safety and order.”

“If there is a clear history and pattern of illegality by a group in a way that threatens the safety of the public, then it might be subject to restrictions,” he said.

He added that the party was also considering banning protests for six hours of the day from midnight to 6 a.m. Last week, the union held an overnight rally in Seoul’s central Gwanghwamun boulevard in the name of a cultural festival, occupying the roads illegally despite police warning.

Asked if the ruling party viewed the union’s protests as illicit, he said that was up to the investigative authorities to decide.

The Democratic Party of Korea and other opposition parties have slammed the amendment as an “attack on the foundation of democracy.”

Rep. Lee Jae-myung, the Democratic Party’s leader, said restricting protests under any circumstances was “unconstitutional.” Lee and Democratic Party lawmakers have regularly attended the weekly anti-Yoon rallies, organized by civic groups affiliated with the party.

Also indicted in the North Korea spying investigation are former officials at the Progressive Party, which was disbanded in December 2014 by the Constitutional Court for its close alignment with North Korea.

Rep. Yoo Sang-bum, the chief spokesperson for the ruling party, said in a statement on Wednesday that investigating North Korea espionage activities was “critical” to protecting the national security.

“It is imperative to leave no suspicion unaddressed,” he said.