Senator Alan Peter Cayetano and several other lawmakers have asked the Supreme Court (SC) to urgently rule on the constitutional voting threshold required in the Senate, warning that failure to do so could cast doubt on the legality of future Senate actions, including the impeachment trial of Vice President Sara Duterte.

In a Manifestation and Motion, the petitioners said the High Court must definitively interpret the constitutional phrase “all its members” and determine the proper voting threshold required under the Constitution.

The group argued that recent developments, including the 17 June special session that elected Senator Sherwin Gatchalian as Senate President, did not render moot their petition questioning the legality of the previous 3 June rump session.

According to the petitioners, Gatchalian’s election neither erased nor corrected the alleged constitutional defects surrounding the earlier proceedings.

“The validity of the 3 June 2026 rump session, together with every official act that purportedly emanated from it, remains an actual and justiciable controversy,” the motion stated.

The dispute centers on the interpretation of Section 16, Article VI of the 1987 Constitution, particularly whether temporary absences or the detention of senators may reduce the number of votes required for official Senate actions.

The petitioners also argued that the respondents wrongly relied on the 1949 ruling in Avelino v. Cuenco to justify the 3 June session, saying the case involved materially different circumstances and predated the 1987 Constitution, which explicitly requires the election of the Senate President by “a majority vote of all its members.”

They warned that leaving the issue unresolved could create uncertainty over the validity of future Senate actions, including committee reorganizations, the election of officers, amendments to impeachment rules, and the coming impeachment trial of Vice President Duterte.

The group also cited the detention of Senator Jinggoy Estrada and the possibility of further arrests of senators as reasons for the Court to immediately settle the issue.

With Duterte’s impeachment trial set to begin on 6 July, the petitioners urged the Supreme Court to exercise its power of judicial review and issue a definitive ruling before the controversy is overtaken by political developments.