The required threshold to convict Vice President Sara Duterte remains fixed at 16 votes, or two-thirds of all Senate members, despite the persistent bickering between the two rival camps in the chamber over quorum-related issues.

Acting Senate President Win Gatchalian said the constitutionally mandated threshold would be strictly adhered to during the VP’s trial at the Senate impeachment court, scheduled for 6 July.

This contradicts the allegations of his predecessor, Senator Alan Cayetano, that the insistence of the Gatchalian-led faction in pushing the leadership revamp on 3 June, with only a 12-member quorum, could set a dangerous precedent by also reducing the threshold needed for a conviction in an impeachment.

“The rules are clear. And the constitutional threshold—16 votes, will be faithfully observed,” Gatchalian said. “Our duty is to follow the Constitution, and that is what we will do.”

Article XI, Section 3(6) of the Constitution sets the required number of votes to convict a high-ranking official at 16, which is equivalent to two-thirds of the 24-member Senate.

A conviction carries a penalty of removal from office and perpetual disqualification from holding one. This could derail Duterte's presidential bid in the 2028 elections. 

Gatchalian claimed that the ongoing internal dispute in the Senate over quorum will not affect the impending impeachment proceedings and that the threshold will remain at 16, regardless of how many senators attend the trial. 

In May, Cayetano and allies attempted to amend the Senate rules to allow senators—for justifiable reasons—to join sessions and cast their vote remotely. 

However, the move was met with fierce objections from the Gatchalian bloc, which accused them of railroading the process ahead of the arrest of Senators Jinggoy Estrada and Bato de la Rosa, thereby allowing them to vote in the impeachment even if they are detained or in hiding.

Earlier, former Senate president Franklin Drilon speculated that the ulterior motive behind such an effort was to outnumber and defeat the Gatchalian bloc if Duterte’s bank records were compelled to be disclosed through a subpoena, as she faces allegations of graft and corruption.

Cayetano’s bloc, mostly composed of senators allied with Duterte, has denounced the leadership change on 3 June, deriding it as unconstitutional for lacking one vote to meet the 13-member majority threshold to conduct business and elect a new Senate president and officers. 

Gatchalian and allies, however, countered that the 12-member quorum was solely based on previous Senate precedents, including the landmark 1949 Supreme Court case (Avelino v. Cuenco), thereby legal. 

The jurisprudence allowed the adjustment of the base number of senators when certain members are legally beyond the Senate's coercive reach.

Because of this, the Gatchalian-led faction insisted that the simple majority is now at 12 because their base number has dropped from 24 to 22 due to the arrest of Estrada and the continued hiding of De la Rosa, who are in Cayetano’s bloc.

Cayetano remains headstrong that he is still the legal Senate president and, as a result, will be the presiding officer in Duterte’s impeachment trial.

The unfazed Gatchalian, however, stressed that he retains control of the chamber, adding that discussions are still ongoing about who in their bloc will preside over the impeachment.

Reports indicate that Senator Chiz Escudero, a lawyer like Cayetano, is being eyed by Gatchalian’s faction as the presiding officer.

The pre-trial conference for Duterte’s impeachment is scheduled for 18 June, with both Duterte’s defense and the House prosecution panel directed to submit their pre-trial briefs by 15 June. 

The VP is facing allegations of betrayal of public trust, culpable violation of the Constitution, graft and corruption, and other high crimes. She was first impeached on 5 February last year. However, the Supreme Court unanimously struck it down on a technicality before the Senate could hold a trial proper. 

The charges are primarily related to the alleged misuse of over P600 million in confidential funds, unexplained wealth, and a plot to have Marcos, First Lady Liza Araneta-Marcos, and former House speaker Martin Romualdez killed.

The secret funds were allocated to her office (P500 million) and the Department of Education (P112.5 million), which she headed for two years from June 2022 to June 2024. 

Duterte has repeatedly dismissed the allegations of wrongdoing, deriding the impeachment proceedings as a fishing expedition and politically motivated, aimed at derailing her plans to run for president in 2028.