Detained Senator Leila de Lima cast her vote at Saint Rita College in Parañaque around 10:15 a.m.
De Lima, who is seeking reelection, was escorted by policemen after being allowed by Muntilupa courts to cast her vote in Paranaque City.
A staunch critic of President Duterte, De Lima was jailed in 2017 on accusation that she got involved in illegal drug trade inside the New Bilibid Prison (NBP) during her stint as Department of Justice secretary.
Self-confessed drug lord Kerwin Espinosa and former Bureau of Corrections officer-in-charge Rafael Ragos recanted their testimonies against De Lima earlier this month.