Lead impeachment prosecutor Gerville Luistro on Friday argued that the constitutional requirement for a two-thirds vote to convict Vice President Sara Duterte should be based only on senators who are within the Senate's "coercive power," saying the law must evolve to address present-day realities.

Speaking in a radio interview, Luistro anchored her position on the Supreme Court's 1949 ruling in Avelino v. Cuenco, which recognized that legislative bodies may compute quorum and voting thresholds based on members who can actually be compelled to attend proceedings.

"The law must evolve in order to respond to the demands of the present time," Luistro said.

She noted that while the Constitution requires the concurrence of "two-thirds of all the members of the Senate" to convict an impeachable official, it does not expressly specify the number 24.

"Hindi naman sinabing 24. Ang sabi, two-thirds of all the members of the Senate," she said.

Luistro argued that the phrase should refer only to senators who remain within the jurisdiction and coercive authority of the Senate.

"So the number should be adjusted and lowered to a number which is within the coercive power of the Senate," she said, emphasizing that the concept of "coercive power" was the governing doctrine in Avelino v. Cuenco.

She illustrated her argument through hypothetical scenarios involving senators who are detained or deliberately absent.

"If your senator is in jail or hiding, are they still representing the interests of the Filipino people?" Luistro asked.

According to Luistro, the Senate exists primarily to represent the people, and only senators who are physically able to participate in the proceedings should be counted in determining the constitutional threshold for conviction.

"Those who can actually attend the hearing, those who can physically vote, and those who ultimately represent the interests of the people should be considered for purposes of determining the two-thirds vote," she said.

Luistro stressed that her position is anchored on constitutional principles rather than political considerations.

"Two-thirds of all," she said. "When we say 'all,' it means all those within the coercive power of the Senate."