Three opposition parties said Sunday they would jointly submit a motion Monday calling for an independent investigation into state agencies’ interference in last year’s presidential election.

They also demanded that the proposed special investigation cover alleged attempts by spy, law enforcement and military agencies to hamper and whitewash inquiries into the cases, which the opposition parties called extensive electioneering involving top government officials.

The bill will be jointly submitted by the floor leaders of the main opposition Democratic Party and two minority parties ― the Unified Progressive Party and the Justice Party.

To pass, the motion must be approved by a majority of lawmakers taking part in a floor vote by a majority of all National Assembly members.

The three parties hold a combined 138 seats at the 300-member National Assembly, while the ruling Saenuri Party has 155 seats.

“President Park and the Saenuri Party will face much more serious resistance from the people unless they accept the bill to appoint an independent counsel team,” DP leader Kim Han-gil said in a news conference.

The bill calls for allowing the independent counsel to probe the cases for up to two months.

The National Intelligence Service and other government bodies are suspected of having conducted online smear campaigns against the main opposition party in a bid to sway public opinion in favor of the ruling party in last year’s presidential election.

Former NIS chief Won Sei-hoon and other officials are on trial on charges of ordering the smear campaign.

NIS agents are suspected of involvement in more than 20 million tweets and retweets supportive of the ruling camp and critical of the opposition.

On Thursday, the Defense Ministry sent 11 cyber warfare officials to the military prosecution, recommending indictment on charges of posting political comments online during the election.

The ministry’s investigation unit dismissed the allegation that the cyber warfare command interfered in last year’s election on an organizational level, despite their breach of military rules on political neutrality.

President Park Geun-hye’s approval rating has dipped under 50 percent for the first time since April, a new Gallup Korea poll showed Friday.

The poll showed that 48 percent of South Koreans approved of the job the president was doing, while 41 percent disapproved and 11 percent did not express an opinion.

Gallup Korea said it questioned 1,207 people between Dec. 16 and Dec. 19, and the survey has a margin of error of plus or minus 2.8 percentage points.

From news reports