Senator Alan Peter Cayetano on Tuesday said lawmakers critical of the Marcos administration now believe they could be the next targets of criminal prosecution.

"We're all on borrowed time," Cayetano told reporters, referring to what he described as mounting legal pressure on opposition and independent lawmakers.

Thousands of INC members and supporters gathered at the People Power Monument to protest the impending plunder case against Marcoleta and to call for what organizers described as fairness and accountability in government.

The demonstration, first held without a permit, caused major traffic disruptions along EDSA and drew a heavy police presence.

Explaining his decision to attend, Cayetano said the turnout convinced him that the issues raised by the protesters resonated beyond the political arena.

"When I saw people coming out spontaneously, I felt I owed it to them," he said.

"The fight is not just in the Senate. It's in the hearts and minds of the Filipino people."

Cayetano linked his concerns to the detention of Sen. Jinggoy Estrada and reports that an International Criminal Court (ICC) warrant could be issued against Sen. Christopher "Bong" Go, although Philippine authorities have not confirmed the existence of such a warrant.

He also referred to Estrada's public claim that he had been encouraged to switch political sides in exchange for avoiding detention, an allegation that has not been substantiated and has been denied by administration officials.

The senator further cited the deployment of National Bureau of Investigation personnel during recent Senate proceedings, saying the incidents contributed to his concern over the current political climate.

"When we saw what happened to Jinggoy, it became a reality for us," he said.

The Ombudsman has said its actions are based on its investigation and applicable laws.

The Marcos administration has repeatedly denied accusations that it is using the justice system to silence political opponents.

Malacañang has said criminal complaints filed against public officials undergo the normal legal process and are handled independently by investigative and prosecutorial agencies.

The Ombudsman has likewise maintained that the case against Marcoleta was filed based on evidence gathered during its investigation, while the National Bureau of Investigation has said its actions in recent Senate incidents were undertaken in compliance with lawful court orders.

Asked whether other senators would also attend the gathering, Cayetano said he expected more members of the minority bloc to arrive, adding that he knew Sen. Imee Marcos had expressed interest in joining.