EXPLAINER: Power struggle rocks the Senate

A power struggle has erupted in the Senate, with Senators Alan Peter Cayetano and Sherwin Gatchalian each asserting their legitimacy to lead the chamber.

During a session on June 3, 2026, Gatchalian was elected Senate President Pro Tempore and acting Senate President after a quorum of 12 senators was established.

Cayetano rejected the move and insisted that he remains the Senate President. He also argued that electing a new Senate leader requires at least 13 votes from the chamber's 24 members, citing the 1987 Constitution and Senate rules.

Aside from installing Gatchalian, the June 3 session also reshuffled the leadership of several Senate committees, including the Blue Ribbon Committee, with Senator Erwin Tulfo replacing Senator Pia Cayetano as chair.

On June 4, Pia Cayetano proceeded with a committee hearing on alleged flood control anomalies even after Tulfo announced its postponement and said the inquiry would resume on June 8.

Pia Cayetano refused to acknowledge the Gatchalian-led June 3 session and called it “invalid.”

“I stand before you today to state clearly and unequivocally—that session was invalid. Wala po silang 13. Kahit Grade 1 marunong magbilang, kailangan ng 13. So hindi, wala ho silang authority gawin ‘yung mga ginawa nila,” she said.

(I stand before you today to state clearly and unequivocally—that session was invalid. They did not have 13 votes. Even a Grade 1 student knows how to count, and you need 13. So no, they don't have the authority to do what they did.)

The Pia Cayetano-led hearing was attended by allied senators and invited resource persons. However, no members of the Senate secretariat were present, and the proceedings were not livestreamed on the Senate's official platforms.

“There are no official Senate hearings scheduled for this morning, and any so-called ‘hearing’ convened by Senators Alan Peter Cayetano, Pia Cayetano, (Robin) Padilla, and (Rodante) Marcoleta has no basis in the rules, calendar, or authority of the Senate,” the Gatchalian bloc said in a statement.

Before the hearing, Alan Cayetano accused the Gatchalian bloc of violating the Constitution and provoking a crisis through the actions taken during the June 3 session.

Former law dean Atty. Mel Sta. Maria said Gatchalian's installation as acting Senate President was legal, arguing that his bloc followed proper procedures when it declared the Senate presidency vacant.

"There is an attempt to create a legal cloud of doubt as to the whole situation in the Senate when there is none. And therefore it is not even a constitutional crisis. Maybe it's not