Photo credit: Chel Diokno

A key constitutional requirement in the impeachment trial of Vice President Sara Duterte remains unchanged, but questions persist over how the required votes should be counted, according to House prosecutor and Akbayan Party-list Representative Chel Diokno.

Speaking ahead of the June 18 pretrial conference, Diokno clarified that the Constitution’s requirement of a two-thirds vote for conviction cannot be altered. However, he said legal uncertainty remains regarding how that threshold should be computed if some senators are unable to participate or are considered beyond the Senate’s “coercive reach.”

According to Diokno, while the number of votes required for conviction is firmly established by the Constitution, the issue of how those votes are counted has yet to be definitively resolved by jurisprudence.

The discussion comes amid continuing debates over quorum, participation, and voting requirements in the impeachment proceedings against Duterte. Questions have also emerged following recent controversies involving Senate leadership and the interpretation of legal doctrines governing legislative attendance and participation.

Diokno pointed out that the Supreme Court has previously ruled that quorum may depend on how many senators are within the Senate’s authority to compel attendance. However, he noted that it remains unclear whether the same principle can be applied to an impeachment court.

Because of the lack of a definitive ruling, Diokno said it is difficult to predict how the Supreme Court would decide should the matter eventually reach the judiciary.

Meanwhile, Batangas Representative Gerville Luistro, who serves as lead prosecutor and chairperson of the House Committee on Justice, said the issue remains open to debate as legal interpretations continue to evolve.

Luistro argued that impeachment proceedings are fundamentally about representation and accountability. She suggested that questions should be raised about whether senators who are unable to attend hearings or cast votes should still be included when determining the number of votes required for conviction.

According to her, the purpose of electing senators is to represent the interests of the Filipino people, particularly during significant national proceedings such as impeachment trials.

While emphasizing that her remarks reflected her personal opinion, Luistro said the issue deserves careful examination, noting that impeachment is one of the few instances where senators directly exercise judgment on behalf of the entire nation.

The debate over quorum and vote computation is expected to remain a key issue as preparations continue for the impeachment proceedings against Vice President Duterte, with legal experts closely watching how the Senate and potentially the courts will address the unresolved constitutional questions.