Senate President Sherwin Gatchalian and Presiding Officer Chiz Escudero during the Senate impeachment hearing last Tuesday, September 22. Photo by Wendell D. Alinea / Senate Social Media Unit
Manuel Mogato | September 23, 2026
MANILA — In what could be a preview of senator-judges’ verdict in the impeachment case of Vice President Sara Duterte, the Senate impeachment court on Wednesday changed its rules, fixing the required number of votes to convict or acquit the vice president.
The senator-judges took a one-day break from Duterte’s trial to resolve Senator Erwin Tulfo’s appeal to change the 16-vote requirement to convict the vice president.
Tulfo argued the impeachment court should not keep the 16-vote requirement because four senator-judges are not present to hear and see witnesses during trial.
Two are in jail for corruption charges; one has been in hiding after the International Criminal Court (ICC) issued an arrest warrant, and the fourth was seeking medical treatment in Europe.
Before the senators-judge panel cast its vote, the prosecution and defense argued their positions on why the court should act on the impeachment charges.
Under the Constitution, a two-thirds vote of all the senators is required to convict an impeachable official, like the vice president. There are 24 senators, and two-thirds is 16.
Last week, four retired Supreme Court justices shared their wisdom on the matter, saying the Senate impeachment court is not under the Supreme Court and imposes its own rules, including changing the voting threshold of 16.
Prosecution panel Manuel Diokno argued the threshold is movable and should be adjusted to the number of senator-judges present during trial.
Defense lawyer Michael Poa agreed that the threshold is movable, but maintained that the 16 votes must be kept because there’s no vacancy in the Senate.
Minority leader Alan Peter Cayetano raised a point of order to stop the impeachment court from voting on Tulfo’s appeal on presiding judge Francis Escudero setting the threshold at 16 votes.
However, 13 senator-judges disagreed with Cayetano. Only six supported Cayetano, and one abstained.
Escudero said the number of senators allowed to vote to convict or acquit will depend on who will present judgment day.
The defense and the minority planned to appeal the decision by asking the Supreme Court to intervene.