Updated

South Korea's opposition lawmakers on Saturday continued their non-stop speeches for a fifth straight day in parliament to block a vote on a government-backed anti-terrorism bill they say would threaten personal freedoms and privacy if passed into law.

Jung Cheong Rae was talking for more than nine hours as of Saturday afternoon as the 17th lawmaker to take the podium since opposition lawmakers decided on Tuesday to resort to a filibuster, the country's first since 1969.

With the filibuster exceeding 90 hours, it is one of the longest in history. In 2011, Canada's New Democratic Party orchestrated a session that lasted for 58 hours.

For their filibuster to succeed, the lawmakers would need to continue their speeches until midnight of March 10, when the current parliamentary session is scheduled to end.

President Park Geun-hye and her ruling Saenuri Party have endorsed the bill granting greater power to Seoul's main spy agency to investigate individuals and groups, pointing to threats posed by North Korea and activities by militant organizations such as the Islamic State group.

Opposition lawmakers say the bill doesn't have sufficient measures to prevent the agency from abusing its powers for civilian surveillance.

The NIS has a history of meddling in politics and spying on civilians and journalists.

Two NIS directors who successively headed the spy service from 1999 to 2003 were convicted and received suspended prison terms for overseeing the monitoring of cellphone conversations of about 1,800 of South Korea's political, corporate and media elite.

Another former NIS chief was sentenced to three years in prison last year after being found guilty of ordering an illicit online campaign to support then-ruling party candidate and current President Park Geun-hye ahead of the 2012 presidential election and smear her main liberal rival, Moon Jae-in.

The Supreme Court later ordered a new trial for Won Sei-hoon after rejecting some of the evidence that was used to convict him at the lower court. It's unclear if or how much the online campaigning helped Park win the 2012 election.