The number of senators required to convict Vice President Sara Duterte in an impeachment trial could still fall below 16, depending on how many lawmakers are able to vote, former Supreme Court Associate Justice Antonio Carpio said.

Speaking at a forum at the Manila Hotel, Carpio said the voting threshold is not fixed and will depend on the total number of active senators present when the Senate sits as an impeachment court. The trial is scheduled to begin on July 6.

Under the Constitution, conviction requires a two-thirds vote of all members of the Senate. However, Carpio explained that the actual number needed may change if some senators are unable to participate.

He cited the case of Sen. Jinggoy Estrada, who is currently detained and under suspension by the Sandiganbayan. Despite his situation, Carpio noted that Estrada remains a senator, but his participation in the vote may be affected.

Meanwhile, Sen. Ronald dela Rosa, who is reportedly in hiding due to an arrest warrant issued by the International Criminal Court (ICC) over the previous administration’s war on drugs, cannot yet be excluded from the voting count as he has not been arrested, Carpio said.

Carpio added that the threshold could further decrease if other senators become unable to vote due to detention or other legal circumstances.

He also warned that the impeachment process could be prolonged if the Senate impeachment court grants a motion to dismiss filed by Duterte’s camp.

In that case, he said, prosecutors are expected to elevate the matter to the Supreme Court of the Philippines, potentially extending proceedings.