South Korea's conservative ruling party is on the verge of a split following President Park Geunhye's parliamentary impeachment last week.

Kim Moo-sung, leader of anti-Park lawmakers in the Saenuri Party, on Tuesday called Park loyalists her "political slaves" in an escalation of harsh rhetoric between rival factions in the largest political party in South Korea.

He told a televised conference that he and fellow lawmakers are considering leaving the party to create a new political group.