WATCH: Trillanes explains decision not to run in 2019

MANILA, Philippines — Opposition Sen. Antonio Trillanes IV on Monday said he is not gunning for any elective post in 2019, but would continue his advocacy of “fighting for the truth [and] criticizing what is wrong.”

Trillanes, instead, threw in his support to fellow ex-mutineer, Rep. Gary Alejano (Magdalo party-list) who filed his certificate of candidacy for a seat in the Senate on Monday.

He said he would show President Rodrigo Duterte, who earlier ordered the senator's arrest, that he could "stand up" against him even without a seat in Congress, "so long as [I am] in the right." 

Trillanes' second term in the Senate is set to end next year. Philippine senators serve a maximum of two consecutive terms with six years per term.

— Kristine Joy Patag