South Korea's ruling Democratic Party(DP) continued to lambast the main opposition's defector-turned-politicians, who suggested that North Korean leader Kim Jong-un's health may be in a grave state.

At a supreme council meeting on Monday, DP Chair Lee Hae-chan said such imprudent responses to speculation about Kim's health from the outside and some media outlets are deplorable and vowed to actively respond to such cases.

Earlier, main opposition United Future Party(UFP) representative-elect Thae Yong-ho claimed that Kim could neither get up nor walk by himself.

The UFP's satellite Future Korea Party(FKP) representative-elect Ji Seong-ho claimed he was 99 percent certain that Kim had died after surgery to treat cardiovascular disease.

On his social media account, DP Rep. Kim Boo-kyum criticized Thae and Ji for threatening national security, adding that they shouldn't be allowed to sit on the parliamentary committees for defense or intelligence.