Main opposition Democratic Party of Korea (DPK) lawmakers, who served as Cabinet members or presidential staffers during the Moon Jae-in administration, hold a press conference to protest the bribery investigation involving the former president at the National Assembly, Sunday. Yonhap

The Democratic Party of Korea (DPK) has decided to actively respond to the prosecution's ongoing bribery investigation involving former President Moon Jae-in, condemning it as a "petty act of political retaliation," party members said Monday.

In strong opposition to the investigation, the main opposition party is considering forming a countermeasures committee.

"There have been discussions within the party about forming the countermeasures committee to better respond to the prosecution's broad-ranged investigation into the former president and the former administration," Rep. Jo Seoung-lae, the opposition party's chief spokesperson, told reporters on Monday, after the party's Supreme Council meeting at the National Assembly.

The proposal to form a countermeasures committee within the party is said to have been initiated by DPK leader Rep. Lee Jae-myung.

Lee raised concerns over the issue during his one-on-one meeting with ruling People Power Party (PPP) leader Han Dong-hoon on Sunday, criticizing the prosecution's investigation into the former president.

"We are seeing an increasing number of excessive actions that could be perceived as political retaliation against the previous administration," Lee said in his opening remarks before the meeting with Han.

Rep. Lee Jae-myung, chairman of the main opposition Democratic Party of Korea (DPK), speaks during a budget policy consultative meeting at the National Assembly in Seoul, Monday. Yonhap

The main opposition party continued its criticisms against the prosecution's investigation into the former president and his family on Monday.

At the party's Supreme Council meeting earlier in the day, DPK floor leader Rep. Park Chan-dae strongly condemned the government.

"While countless patients are unable to find emergency rooms, this ruthless administration is fixated solely on political retaliation, showing no regard for the lives of the people," he said.

Park also criticized the prosecution's recent investigation into first lady Kim Keon Hee, arguing that their claim of "equality before the law" is inconsistent.

On a related note, DPK party leader Lee Jae-myung plans to visit Moon on Sunday. The visit has been delayed from the initial date of Aug. 25 due to Lee's recent COVID-19 diagnosis.

Ruling People Power Party floor leader, Choo Kyung-ho left, speaks during the party's Supreme Council meeting at the National Assembly in Seoul, Monday. Yonhap

Meanwhile, PPP floor leader Rep. Choo Kyung-ho defended the prosecution's actions at Monday's Supreme Council meeting in the National Assembly, stating, "It is not right to halt legitimate investigations conducted in accordance with laws and regulations."

Saying a direct investigation into Moon is expected to be inevitable, Choo also criticized the main opposition party for its double standards.

"When former presidents Park Geun-hye and Lee Myung-bak were imprisoned, and numerous figures from the conservative camp were detained during the early days of the Moon Jae-in administration, the DPK fervently supported these actions, calling them ‘clearing deep-rooted evils.' Now that they are the opposition, they label similar actions as ‘political retaliation.' Few will sympathize with the party's double standards," Choo said.

The prosecution has been investigating allegations of a quid pro quo involving Moon's former son-in-law, who was appointed to an executive position at a low-cost carrier founded by former lawmaker Lee Sang-jik despite lacking experience in the aviation industry.

The prosecutional inquiry is focused on whether this appointment was linked to former Rep. Lee's appointment as head of the Korea SMEs and Startups Agency in March 2018 during Moon's presidency. Moon's son-in-law, surnamed Seo, was hired four months after Lee assumed leadership of the agency.