The Senate impeachment court set 23 September to resolve the lingering question of whether to lower the 16-vote threshold required to convict and remove Vice President Sara Duterte from office, amid the prolonged absence of several senator-judges from her trial.

The decision was reached after Senator Erwin Tulfo questioned whether the base count for the two-thirds vote for conviction includes all 24 senators, consistent with Presiding Officer Chiz Escudero’s 6 July ruling, or only those present during the voting.

He warned that insisting on the voting basis being fixed at 24, notwithstanding the absence of four senator-judges, will result in an “acquittal by default” regardless of how the evidence is presented.

Senator-judges will decide by a vote after the defense and the prosecution give their respective position in an oral argument, which will be held on the same day. 

Before this, the impeachment court will schedule a meeting on 16 September with amici curiae (friends of the court, or legal experts) to solicit their differing legal views on how the court will interpret the constitutional provision regarding the threshold before it hands down a decision. 

The trial will be suspended that day to make way for the meeting and budget deliberations. 

Tulfo raised the issue barely one hour after Day 23 of the impeachment trial commenced. His manifestation prompted a 30-minute recess and sparked another 30-minute debate among the senator-judges, leading Escudero to adjourn the trial afterward. The witness scheduled to testify was rescheduled for Monday.

Tulfo highlighted the urgent need to resolve the threshold issue, as the trial had already entered its second month. He also cited the prosecution dropping several witnesses from its lineup to expedite the proceedings to meet the intended timeline to conclude the trial before Christmas. 

“This is something that the body needs to discuss and decide on sooner than later, Mr. Presiding Officer. I move that we do so in earnest, because it seems like we’re running out of time,” Tulfo warned.

The Constitution requires two-thirds—equivalent to 16 votes—of the 24-member Senate to convict an impeached official. 

Since Senators Jinggoy Estrada and Rodante Marcoleta are detained on plunder charges, while Senator Bato dela Rosa remains in hiding to evade an International Criminal Court warrant, they have been unable to attend the trial since it started on 6 July. Senator Loren Legarda, meanwhile, has been on medical leave since 3 August amid a preliminary investigation by the Ombudsman into plunder and graft complaints. 

While Escudero’s 6 July ruling was anchored on Bayan v. Zamora, where the Supreme Court upheld that the Senate is composed of 24 members, Tulfo pointed out that the Senate “consistently relied” on Avelino v. Cuenco to establish a quorum. 

Ghost of 3 June ‘illegal coup’

Senator Pia Cayetano, a member of the minority allied with the absent senators, assailed Tulfo’s remarks. She argued that the ruling was deliberately weaponized by the majority to declare a quorum on 3 June and to declare all Senate positions vacant, including the Senate presidency then held by her brother, Alan Cayetano, despite falling short of the 13-member majority threshold by one vote. 

“That is not accurate, Your Honor. These 12 members of the Senate chose to use Avelino v Cuenco for their own purposes…This body did not agree to that,” Cayetano pointed out. 

The exchanges prompted Escudero to shelve and consider Tulfo’s manifestation on the conviction threshold in an appeal of his 6 July ruling, where he maintained that the base vote remains at 24 regardless of how many senators are present in the voting. 

Still, Cayetano objected, citing the same ruling by Escudero, requiring those who would dare to assail his decision to go to the SC.

Due to this, Cayetano warned that reopening the discussion on the 6 July ruling risks being “unconstitutional,” since the Senate impeachment court has already made a decision and must abide by it. 

“The Constitution is clear that the interpretation of the Constitution belongs to the Supreme Court. There is nothing written in it that gives anyone else the authority to do so,” Cayetano argued, adding that even the Senate holds no power to interpret the Charter.

According to Escudero, lowering the number needed for conviction would also effectively reduce the threshold for acquittal. 

Meanwhile, Cayetano suggested that the Senate also take a position on whether to allow Estrada and Marcoleta to participate and cast their votes despite their detention.

Tulfo, however, countered that the decision on whether to allow them is beyond the Senate’s control and within the Sandiganbayan's. 

Senator Raffy Tulfo chimed in, warning that since Estrada and Marcoleta have been unable to monitor the proceedings, they cannot “vote intelligently.”

Escudero settled the debate by stating that it is the Senate—as a legislative body—that will decide whether to ask the Sandiganbayan to allow the two detained senators to participate in the trial while facing charges.