President Yoon Suk Yeol expressed deep concerns over the latest North Korean spying scandal during a dinner with the newly elected leaders of the ruling People Power Party on Monday, according to sources familiar with the matter Wednesday.

Several ruling party sources said that the president was looking at the counter-North Korean meddling investigations seriously, referring in particular to the country’s main umbrella labor union -- the Korean Confederation of Trade Unions -- and a number of its officials’ alleged ties to North Korea.

The People Power Party chair Rep. Kim Gi-hyeon said Tuesday that his party was “declaring a war against North Korean spying and pro-North Korea activities.”

Rep. Tae Yong-ho, who sits on the ruling party’s supreme council, said on the same day that the revisions to the law that take away the intelligence service’s ability to launch counter-espionage operations needed to be reversed.

He said that the revised law passed unilaterally by the Democratic Party of Korea during the Moon Jae-in administration would weaken the country’s ability to respond to North Korea’s spying efforts.

On some of the KCTU official’s alleged involvement in espionage, Tae noted that the labor union has engaged in “curious activities.”

“There is a public and consistent record of the labor union protesting against South Korea-US joint military exercises and calling for withdrawal of US forces from the country. This is a questionable cause for a labor union to be pursuing,” he said.

The KCTU has vehemently denied all accusations, saying that they were “complete fiction” in a statement on Tuesday.

“The intelligence service is pulling the same dirty trick it’s pulled in the past, going on a hunt for supposed communists,” its official said in a phone call with The Korea Herald.

The main opposition Democratic Party of Korea’s chair Rep. Lee Jae-myung on Wednesday visited the Seoul headquarters of another major labor organization, the Federation of Korean Trade Unions, and said the Yoon administration was “demonizing labor unions.”

Last week, ruling party Rep. Yoo Sang-bum on the parliamentary intelligence committee told reporters during a closed-door briefing that the spy service was investigating alleged North Korean interference in some of the largest union-led strikes last year.

But the intelligence committee’s opposition lawmakers argue that the claims of North Korean presence in labor unions are likely the spy service’s bid to retain its authority investigate espionage crimes.

One Democratic Party lawmaker on the committee told The Korea Herald on Wednesday such espionage investigations “usually take years, even a decade, and proceed covertly.”

“The way the so-called spy cases are being publicized is highly unusual, and appears to be motivated by the intelligence agency’s desire to keep a hold of its investigative authority.”