House prosecutor and Akbayan party-list Rep. Chel Diokno on Wednesday said changing the number of senator-judges counted in determining the impeachment threshold would not necessarily favor the prosecution, as it would affect both conviction and acquittal.

During oral arguments in Vice President Sara Duterte’s impeachment trial, Diokno said excluding senators who are unable to participate would reduce the number of votes needed on both sides.

“A different denominator does not guarantee conviction. It changes the arithmetic on both sides. Both parties would be affected by the count,” Diokno said.

“That is why the constitutional issue should not be reduced to lowering the vote to convict. The more accurate question is how many senators must be counted,” he added.

The Senate impeachment court is reconsidering Presiding Officer Francis “Chiz” Escudero’s earlier ruling that 16 votes, or two-thirds of all 24 senators, are required to convict Duterte.

Diokno said the prosecution sought clarity on the proper interpretation of the constitutional two-thirds requirement but acknowledged the Senate’s authority to resolve the issue.

“The articles do not change. The burden, imposed upon the prosecution, does not change. In the same breath, the responsibility of this Court to render independent judgment remains the same,” he said.

“Whatever the Court decides, the prosecution will respect that decision. Because ultimately, two-thirds remains two-thirds.”

Threshold ‘not fixed’

Diokno also cited the positions of the four amici curiae invited by the impeachment court, saying their differing interpretations showed that the number needed for conviction was not necessarily fixed at 16.

“Four amici, different approaches, different reasoning, yet all are one in saying that the number to convict is not fixed at 16. All four have concluded expressly or essentially that 16 is not an absolute number,” he said.

Three of the four legal experts had earlier said the impeachment court could depart from the 16-vote threshold, while former Chief Justice Hilario Davide Jr. argued that the computation should be based on senators qualified to participate and vote.

Diokno also argued that senator-judges themselves have a duty to participate meaningfully in the proceedings, citing the constitutional principle that public office is a public trust.

“Public officials exercise authority in trust for the people. And because power is held in trust for the people, power carries with it accountability,” he said.

He argued that it would be difficult for a senator to validly decide the case without having participated in the trial or heard the evidence.

Diokno warned that always requiring 16 votes even when some senators are legally or practically unable to participate could result in what he described as an “acquittal by default.”

“That would be tantamount to an acquittal by default, a failure to arrive at the threshold number caused not by the judgment of the incapacitated senators but by their mere inclusion in the denominator,” he said.

Four senators have been absent from the proceedings for varying reasons. Senators Jinggoy Estrada and Rodante Marcoleta are detained over separate plunder cases, Sen. Ronald “Bato” dela Rosa is in hiding amid an International Criminal Court arrest warrant, while Sen. Loren Legarda has been abroad on medical leave.

The oral arguments stemmed from Sen. Erwin Tulfo’s request for clarification on whether senators unable to participate should still be included in computing the two-thirds threshold.