South Korean ruling party lawmaker: ”If you don't request an investigation into the assassination of Lee Jae-myung, I will sue you for false accusations”

Rep. Na Kyung-won of the ruling People Power Party of South Korea has requested the Democratic Party of Korea (DPJ) to investigate the information about the assassination of DPJ Chairman Lee Jae-myung.
If they don't, I will sue them for false accusations." On the 20th, Rep. Na posted on Facebook, "If there was information about an 'assassination,' please reveal the source of the information and who provided it.
"Isn't it natural that they should file a complaint and request an investigation?" he wrote. Prior to this, the Democratic Party had said, "There is a plot to smuggle a Russian-made gun and assassinate Chairman Lee.
The Democratic Party said that such information had been conveyed to many lawmakers, but after Rep. Na raised suspicions that the allegations were fabricated, the party filed a defamation lawsuit against him.
Rep. Na said, "According to what I confirmed with the police in my office, there have been no complaints, accusations or requests for investigation regarding the assassination of Lee."
"Wouldn't it be suspected that they are aiding and abetting an assassination if they receive information of an assassination and take no action?" he continued.
"What they are doing is tantamount to admitting that the information about the 'assassination' was fabricated," he emphasized.