Three opposition parties agreed Monday to jointly propose a bill for an independent counsel probe and request a parliamentary investigation into an opinion-rigging scandal involving former members of the ruling party.

The main opposition Liberty Korea Party, the Bareunmirae Party and the Party for Democracy and Peace said they would normalize the legislature if the ruling Democratic Party of Korea accepts their proposal for a special probe. The Liberty Korea Party and the Bareunmirae Party have been boycotting legislative sessions over another disputed bill.

“We agreed that a probe by an independent counsel free from political influence is inevitable as the police and the prosecution have limits in fulfilling their responsibilities of finding out the truth,” the three opposition parties said in a joint statement issued after a meeting of their leaders.

The ruling party reaffirmed its position that it will wait for the police to complete its investigation.

The Democratic Party has slammed the demand for a special probe as a political offensive ahead of the local elections in June. 

“It is our leadership’s position that we can accept a special probe if the police investigation results are insufficient,” the Democratic Party Floor Leader Woo Won-shik told reporters Monday.

The three opposition parties hold a combined 160 seats, more than half of the 293 registered lawmakers, which is enough to put the special probe bill to vote at the plenary session.

However, as the bill’s passage requires the support of at least two-thirds of the legislature, an independent counsel probe cannot take place without the Democratic Party’s approval.

An influential blogger who goes by the alias “Druking” and two others were arrested and indicted earlier this month for allegedly using a computer software in January to jack up the number of “likes” for online comments critical of the Moon Jae-in administration on news articles carried by the Internet portal Naver.

The case has sparked an intense political dispute as Rep. Kim Kyoung-soo of the Democratic Party, one of President Moon’s most trusted aides, was found to have been in contact with Druking since 2016.

Opposition parties speculate that Druking could have rigged online opinions even in the lead up to the presidential election in May 2017.

Rep. Kim revealed that after Moon won the election, the blogger asked him for job favors, which were turned down.

Opposition parties have criticized the police for being slow and lax in its probe as the case involves the president and Kim.

The ruling party revoked the party membership of Druking and another suspect after they were detained.

The three opposition parties said Monday they share the view that the illegal opinion-rigging case “disrupted common sense, justice and the foundation of democracy.”

The parties said, however, they would try to refrain from partisan squabbles this week ahead of the inter-Korean summit which takes place on Friday at the border truce village of Panmunjeom.

The parties also said they agreed to join forces to push for an electoral system reform and a constitutional amendment to shift to a government form that decentralizes power and allows cooperative governance.

By Kim So-hyun (sophie@heraldcorp.com)