Senator-judge Alan Peter Cayetano has warned against changing the voting rules for the impeachment case against Vice President Sara Duterte while the trial is already underway.

The issue came up again after Senator-judge Erwin Tulfo sought clarification on whether 16 votes should still be required to convict Duterte, based on the two-thirds requirement covering the full 24-member Senate.

During Monday’s (Sept. 14) proceedings, Cayetano asked former Sandiganbayan Presiding Justice Amparo Cabotaje-Tang about the possible effect of changing rules in the middle of a case.

Tang said rules of evidence cannot be changed while a case is being prosecuted.

“So, kung gusto talagang ma-convict, biglang ibahin y’ung rules, isa na lang out of three. Would that give justice?” Cayetano asked.

“No, sir, and that is not allowed,” Tang replied.

“OK. Sa inyo [hindi allowed], sa amin baka [allowed],” Cayetano said.

The Senate impeachment court is set to hear retired Chief Justices Artemio Panganiban and Reynato Puno, as well as retired Associate Justice Adolfo Azcuna, on Wednesday as amici curiae, or friends of the court, who will provide legal views on the disputed voting requirement.

Former Chief Justice Hilario Davide Jr. will also submit a legal memorandum before the prosecution and defense present their arguments on September 23.

Cayetano said the issue could have consequences beyond the current impeachment case.

“This impeachment court’s decision and how we conduct ourselves and whether we follow the rules or not will determine our destiny not only in the next two years, 10 years, maybe in the next 40 years,” he said.IMT