Hwang said President Moon Jae-in should not turn a deaf ear to the public's call to dismiss the minister amid the prosecution's investigation into the allegations against his family.

"Minister Cho should voluntarily step down from the post and face the prosecution's probe," Hwang said.

Hwang followed suit after Rep. Park In-sook of the LKP had her head shaved Tuesday. Rep. Lee Un-ju, an independent lawmaker, did the same thing last week.

President Moon Jae-in sent his senior secretary for political affairs, Kang Gi-jung, to deliver a message of "concern and worry" over Hwang's move.

Kang asked Hwang to reconsider the head-shaving decision, according to Cheong Wa Dae spokesperson, Ko Min-jung. In response, the LKP leader stressed that Moon should fire Cho.

Cheong Wa Dae wants to resolve a mountain of pending issues related to people's livelihoods via dialogue, Ko added.

The LKP's fierce protest came as Moon appointed Cho as the new minister last week despite the prosecution's probe into corruption allegations involving his family members.

The prosecution is looking into a suspicious investment by Cho's family members in a private equity fund.

Cho's wife was also indicted for allegations that she played a role in fabricating a school certificate for her daughter.

Cho has denied his role in the allegations during a parliamentary confirmation hearing held Sept. 6.

Moon said last week if he does not appoint Cho solely due to suspicions, the move will make a bad precedent.

The ruling Democratic Party and the minor liberal Party for Democracy and Peace condemned Hwang's move as a political gambit aimed at intensifying partisan wrangling.

"Hwang's move is nothing but an act to spark political strife or to reaffirm his (political) existence," the DP said.

Since the appointment, conservative opposition parties have condemned Moon's appointment and called for Cho to be dismissed.

In particular, the LKP took issue with the ruling party and the government's move to revise a guideline over the prosecution's handling of the media.

They will hold a consultative meeting Wednesday to discuss ways to limit prosecutors' alleged leak to the press of details about their probes and indictments of suspects.

They are considering setting a new punitive stipulation under which the justice minister would be able to order surveillance on prosecutors who leak details about investigations to the media.

In South Korea, the justice minister oversees the prosecution in terms of human resources and administration.

"They are hampering the prosecution probe by hook or by crook. They are effectively blocking the investigation (into Cho's family)," LKP floor leader Na Kyung-won said at a meeting with members of the leadership council.

The minor opposition Bareunmirae Party began to collect signatures from its lawmakers to submit a proposal to launch a parliamentary probe into Cho.

A proposal to demand a parliamentary probe requires at least the participation of one-fourth of existing lawmakers, which means 75. As the BP controls 28 seats in the 297-member parliament, it needs cooperation from the LKP to submit the proposal.

The ruling DP, meanwhile, slammed the opposition parties for focusing on political wrangling and shunning calls to improve people's livelihoods.

"It is the prosecution that will investigate," DP floor leader Lee In-young said at a party meeting. "It is time for the National Assembly to play a responsible role for the people's lives." (Yonhap)