The panels had an unsuccessful meeting Wednesday where they discussed disciplinary measures for the three lawmakers.

The lawmakers have come under fire for holding a public hearing last week in which they invited a far-right figure who claims that North Korean troops were involved in the pro-democracy uprising in the southwestern city of Gwangju in 1980.

During the hearing, the lawmakers allegedly made remarks disparaging the democracy movement, with one of them claiming that it was a riot turned into a revolt by people with political purposes.

On May 18, 1980, the military carried out a bloody crackdown on demonstrators, including students, in Gwangju who were protesting against then-President Chun Doo-hwan, who took power in a military coup a year earlier.

The tank-led quelling of the uprising led to the deaths of around 200 people and 1,000 others were injured, official data showed.

The controversy has dented the party, which is eager to muster support from conservative voters ahead of its leadership election.

But Thursday's decision keeps Kim Jin-tae and Kim Soon-rye on track to take part in the election. They are running for party leader and senior official posts, respectively.

The ruling Democratic Party and three rival parties have filed a petition against the lawmakers with the parliamentary special committee on ethics over their conduct.

President Moon Jae-in has rejected two LKP nominees as members of a new fact-finding mission designed to verify suspicions that the then military government and its conservative predecessors may have covered up the truth about the bloody crackdown on the 1980 movement. (Yonhap)