A Seoul court on Tuesday sentenced an opposition lawmaker to a suspended prison term for detonating a tear gas bomb in the National Assembly’s main chamber in protest of the free trade agreement with the U.S.

Kim Sun-dong of the main opposition Democratic United Party, who was affiliated with the minor progressive Democratic Labor Party at the time, was found guilty of using tear gas to block the ruling party’s unilateral move to put the long-pending trade pact to a floor vote in a snap parliamentary session in November 2011.

Despite his violent attempt to block the vote, the bill passed with a majority mostly due to support by ruling party lawmakers.

The Seoul Southern District Court sentenced the lawmaker to one year in prison, suspended for two years.

Following the ruling, Kim said he would appeal the decision to a higher court.

The activist-turned-politician will lose his legislative seat if the sentence is finalized by the Supreme Court. (Yonhap News)