Senator-judges examine witness testimony on the confidential funds of the Office of the Vice President (OVP) and the Department of Education’s (DepEd) as the Senate impeachment court convened for Day 15 of the trial of Vice President Sara Duterte on Wednesday, August 12, 2026. Voltaire Domingo, Senate Social Media Unit/File
MANILA — The Senate impeachment court has named four retired Supreme Court justices as amici curae who will advise the court on how many votes are needed for the acquittal or conviction of Vice President Sara Duterte.
Retired Chief Justices Artemio Panganiban and Reynato Puno, as well as Retired Associate Justcie Adolfo Azcuna have confirmed their physical attendance on September 16 before the impeachment court.
A third retired chief justice, Hilario Davide, committed to submit a legal memorandum. Davide as chief justice presided over the country's first ever impeachment trial, that of former president Joseph Estrada.
"The Impeachment Court commends the prompt cooperation of these distinguished jurists. Securing their counsel marks a critical procedural milestone, ensuring that this trial proceeds anchored on verified constitutional bedrock," the court's spokesperson Regie Tongol said.
Tongol said the court was reserving the right to invite additional experts should it feel that is needed. He said the court has right of first review of amici curae's written advisories and would not make those known before these are publicly presented.
The impeachment court tapped advisers after Sen. Erwin Tulfo appealed the July 6 ruling that the concurrence of 16 senators or two-thirds of the full 24-member Senate is needed to convict Duterte and ban her from government.
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Tongol said only senator-judges will be allowed to ask questions with floor time controlled by the presiding officer, while the prosecution and defense will just sit and listen.
Both sides will get 15 minutes each to argue their positions before the court on September 23, to be followed by questions from the senator-judges. The senator-judges will vote afterwards to settle the appeal.
"The Impeachment Court is not leaving constitutional math to guesswork or chance," Tongol said. "The Impeachment Court will not rush the resolution of this constitutional threshold. Doctrinal Accuracy and constitutional exactitude take precedence over speed."
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