The National Assembly passed a contentious bill Thursday that would expedite the launch of a new investigative body handling high-profile corruption cases amid fierce protest from conservative opposition lawmakers.

The revision bill on the Corruption Investigation Office for High-ranking Officials (CIO) law passed a plenary session in a 187-99 vote. One lawmaker abstained.

The proposal was tabled at the last plenary meeting of the regular parliamentary session Wednesday, but the main opposition People Power Party (PPP) thwarted parliamentary voting on it by launching a filibuster.

The bill aims to remove veto power held by the two PPP-side members of the seven-person committee entrusted to select candidates for the inaugural chief of the CIO.

Due to their veto, the committee failed to reach an agreement in its three rounds of meetings last month, stalling the launch of the investigative organ championed by President Moon Jae-in and the ruling Democratic Party (DP).

As National Assembly Speaker Rep. Park Byeong-seug banged the gavel to announce the bill's passage, PPP lawmakers erupted into united chanting in protest, while ruling party representatives welcomed it with wild clapping.

"I feel miserable and enraged. (PPP) will stop this atrocious administration's tyranny in cooperation with the people," PPP floor leader Rep. Joo Ho-young told reporters after the bill's passage.

DP Chairman Rep. Lee Nak-yon, on the other hand, wrote on his Facebook page, "If the CIO goes into operation, illegitimate privileges and unreasonable practices among those who have power will disappear and the bureaucracy will become cleaner."

The speaker then tabled another contentious bill -- a revision to the National Intelligence Service Korea Act -- but voting on the bill was put on hold as the PPP started another round of filibustering.

The National Assembly law allows a filibuster to continue indefinitely while the DP, which commands a majority of the 300-seat chamber, can break it with 180 votes, 24 hours after it began.

But the DP said it will not invoke its right to halt the filibuster to respect the opposition's parliamentary debating, leaving it up to the rival party to decide whether it will continue the filibuster throughout the one-month extraordinary session that kicked off earlier in the day. An end to the ongoing marathon speech immediately opens up voting on the tabled bill.

The tabled bill aims to relocate the state spy agency's authority to conduct anti-communist investigations to the police, in a bid to block its meddling in domestic politics.

Combined with the national police act revision, which passed the assembly earlier this week, the two bills handled Thursday will back up Moon's push to reform powerful state institutions, including the prosecution service, if both of them finally win a parliamentary nod.

One more contentious bill, on prohibiting the launch of anti-Pyongyang leaflets across the inter-Korean border, also remains pending at the assembly due to opposition protests as of Thursday. (Yonhap)