MANILA – Lawyer Vic Rodriguez has asked the Supreme Court to nullify the Senate Impeachment Court’s decision lowering the voting base for conviction in the impeachment trial of Vice President Sara Duterte.

In a petition for certiorari, Rodriguez also asked the high court to issue a temporary restraining order against the implementation of the impeachment court’s Sept. 23 ruling.

“Petitioner respectfully submits that there is a serious constitutional question, a clear need to preserve the status quo, and substantial public interest in ensuring that an impeachment conviction an act of extraordinary constitutional consequence is not rendered under a voting standard that is itself under serious constitutional challenge,” Rodriguez said.

Rodriguez, who filed the petition as a taxpayer and citizen, argued that the impeachment court’s ruling could establish a mechanism allowing the constitutional voting requirement to be altered by the same body whose powers are governed by the provision.

“It would establish a mechanism whereby an express constitutional voting requirement could be modified by a ruling of the very body whose powers are being regulated by that constitutional provision,” he said.

He maintained that because the Senate has 24 members, conviction requires 16 affirmative votes, regardless of whether some senators are absent or unable to participate in the proceedings.

“Absence, non-participation, abstention, temporary incapacity, or inability to participate in the proceeding does not, standing alone, remove an incumbent Senator from the constitutional membership of the Senate,” Rodriguez said.

Rodriguez argued that reducing the voting denominator from 24 to 20 makes conviction easier and is therefore “not neutral.”

“Because the Tribunal’s ruling effectively modifies an express constitutional provision without constitutional authority to do so, it should be annulled for grave abuse of discretion,” he said.

The impeachment court on Wednesday voted to overturn Presiding Officer Francis “Chiz” Escudero’s July 6 ruling that two-thirds of the full 24-member Senate, or 16 votes, was required for conviction.

The reversal was approved by 13 senator-judges, with Escudero casting the lone dissenting vote. Minority Senator-judge Mark Villar voted in favor of revising the threshold.

Six senator-judges did not participate in the vote: Alan Peter Cayetano, Pia Cayetano, Christopher “Bong” Go, Imee Marcos, Robin Padilla and Camille Villar.

Escudero subsequently issued the court’s new controlling order, which provides that the constitutional phrase “all the members of the Senate” refers to senators who are legally and factually capable of participating in the proceedings at the time of the vote.

The ruling allows the exclusion from the voting base of senators who are detained, suspended or otherwise legally restrained from exercising their functions; senators whose whereabouts are unknown while being sought by authorities; those suffering from physical or medical incapacity; senators beyond the coercive processes of the Senate; and others similarly situated.

Escudero said the interpretation would apply pro hac vice, or only to the present impeachment proceedings.

“This ruling and interpretation of the court shall operate pro hac vice or for this occasion only.”

“It shall not constitute to a binding precedent in any future impeachment proceedings,” he said.

The court also ruled that if the two-thirds computation results in a fraction, the required number of votes would be rounded up to the next higher whole number.

The impeachment court earlier heard oral arguments on whether to retain Escudero’s original ruling after Senator-judge Erwin Tulfo sought its reconsideration.

If convicted, Duterte would be removed from the vice presidency and permanently disqualified from holding public office.