A progressive South Korean party decided Wednesday to oust two pro-North Korean lawmakers at the center of political controversy in the new National Assembly session.

The move by the beleaguered Unified Progressive Party (UPP) will apparently spur efforts by conservative lawmakers to deprive Reps. Lee Seok-gi and Kim Jae-yeon of their seats.

The duo has faced weeks of pressure to voluntarily step down amid accusations that they were involved in the UPP's alleged rigging in selecting proportional representation candidates for the April parliamentary election.

Lee and Kim also have become the target of harsh attacks from conservatives, including some major newspapers, due to their past activities sympathizing with North Korea. They allegedly espoused the communist nation's guiding "juche" philosophy of self-reliance.

In a late-night announcement following several hours of discussions, the UPP's disciplinary committee said it decided to expel the lawmakers.

The committee ruled they violated party rules and severely impaired its efforts at a image makeover.

Lee and Kim have a chance to appeal the decision.

But lawmakers at the conservative ruling Saenuri Party are pushing to deprive them of parliamentary posts -- a move that requires separate voting in the National Assembly.

Ways to deal with North Korea are a political hot issue in South Korea.

South Korea remains technically at war with North Korea since their 1950-53 war ended in a cease fire. The North carried out two deadly attacks on the South in 2010, killing 50 soldiers and civilians. (Yonhap News)