The Senate impeachment court set 23 September for resolving 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 date 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 Senator Chiz Escudero’s 6 July ruling, or only those who are present during the voting.

Tulfo warned that insisting on the vote being based on 24 senators, notwithstanding the absence of four senator-judges, will result in an “acquittal by default” regardless of how the evidence is presented.

Senator-judges will vote after the defense and the prosecution shall have given their respective oral arguments, which will be held on the same day.

Before this, the impeachment court will meet on 16 September with amici curiae (friends of the court or legal experts) to solicit their views on how the court should interpret the constitutional provision regarding the vote threshold.

Tulfo raised the issue on Day 23 of the impeachment trial. 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 has 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 said.

The Constitution requires a two-thirds vote of the 24-member Senate — equivalent to 16 votes — to convict and oust 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 against her.

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, Sen. Alan Peter 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 exchange prompted Escudero to consider Tulfo’s manifestation an appeal of his 6 July ruling where he maintained that the base vote remained at 24 regardless of how many senators were 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 it being “unconstitutional,” since the Senate impeachment court had 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 the Senate has no power to interpret the Constitution.

Meanwhile, Cayetano suggested that the Senate 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 to vote was beyond the Senate’s control and with the Sandiganbayan.

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.