Twelve senators declared Senate leadership posts vacant and installed Senator Sherwin Gatchalian as acting Senate president on June 3, 2026, a move rejected by Senate President Alan Peter Cayetano as an unconstitutional coup.
Retired Judge Meinrado Paredes warned on June 4, 2026, that the leadership standoff between the two rival blocs could reach the Supreme Court and spark a full-blown constitutional crisis.
The leadership conflict disrupted Senate operations, forcing staff to work from home, blocking media access, and resulting in competing commands over a Senate Blue Ribbon Committee investigation.
A DISPUTE over who controls the Senate has raised the possibility of a Supreme Court (SC) case, after two blocs claimed authority to lead the chamber.
The Senate cannot function normally if senators disagree over who may preside over sessions, control committees, direct staff and manage security inside the chamber. It may also affect the impeachment proceedings against Vice President Sara Duterte, where the number of votes needed for conviction is central.
At the center of the conflict is the question of which bloc holds the legitimate Senate majority.
Battle over the majority
The leadership dispute in the Senate could develop into a constitutional crisis if rival Senate blocs continue to assert authority and the chamber’s functions are impaired, Retired Regional Trial Court Judge Meinrado Paredes told SunStar Cebu on Thursday, June 4, 2026.
“The minority is insisting that it is the majority,” Paredes said, adding that both camps are expected to press their claims.
On Wednesday, June 3, 12 senators declared key Senate posts vacant and installed Sen. Sherwin “Win” Gatchalian as acting Senate president.
The bloc said Senate President Alan Peter Cayetano had lost control of the chamber after a quorum was declared. This move was based on the SC’s Avelino v. Cuenco ruling in 1949, according to Gatchalian.
Cayetano rejected the move as unconstitutional and said he remains the legitimate Senate president.
That set up competing claims over who may lead sessions, control Senate operations and supervise committee hearings.
Why the numbers matter
Cayetano’s camp said the June 3 proceedings were invalid because the Constitution provides that the Senate is composed of 24 members. Under that position, 13 senators are needed to reach quorum and conduct business and elect officers.
The Gatchalian bloc said 12 senators were enough because the working base should be 22, not 24. It cited the Avelino v. Cuenco ruling and said two senators were not available to be compelled to attend because of the cases involving Sen. Ronald “Bato” dela Rosa and Sen. Jinggoy Estrada.
Dela Rosa has gone into hiding after an International Criminal Court warrant. Estrada was arrested on a plunder charge linked to alleged kickbacks from flood control projects.
Aside from Gatchalian, the other senators in the 12-member bloc are Majority Leader Juan Miguel “Migz” Zubiri, Francis “Chiz” Escudero, Bam Aquino, Erwin Tulfo, Raffy Tulfo, Risa Hontiveros, Francis “Kiko” Pangilinan, Lito Lapid, Panfilo “Ping” Lacson, Vicente “Tito” Sotto III, and JV Ejercito.
Malacañang recognized the leadership change. Palace Press Officer Undersecretary Claire Castro said they respected the decision of the new majority.
Cayetano called the move an “illegal coup d’état.”
“Ang tingin ba ng 12 senador ay basta kakampi mo ang Malacañang ay wala ng batas? Kung titingnan ng rule 1 and 2 ng Senado, na ayon ito sa Philippine Constitution, para i-elect ang Senate president at Senate president tempore ay kailangan 13. So paano po nila aalisin si Sen. Loren Legarda kung 12 lang sila?” he said in a Facebook Live stream on Wednesday.
(Do the 12 senators think that just because Malacañang is on your side, there is no more law? If we look at Rules 1 and 2 of the Senate, which are based on the Philippine Constitution, 13 votes are needed to elect the Senate President and Senate President Pro Tempore. So how will they remove Sen. Loren Legarda if there are only 12 of them?)
How the courts could get involved
Paredes said either side may go to the SC through a petition alleging grave abuse of discretion amounting to lack or excess of jurisdiction.
That route would ask the High Court to decide which group holds the legitimate majority and who has authority to lead the Senate.
“The referee in a constitutional crisis is the Supreme Court,” Paredes said.
He said a party may also seek a temporary restraining order, as part of a legal challenge. But he said the realities inside the Senate could make the dispute harder to manage, especially if the fight reaches internal operations and security.
Paredes said the group recognized as the majority traditionally exercises influence over the Senate sergeant-at-arms and internal operations. At the same time, he questioned whether senators could be restricted from entering the chamber because of their constitutional positions.
He said majority rule remains a key principle in a democratic institution. That makes the finding of the true majority central to the dispute.
How the fight reached a Senate hearing
The leadership fight spilled into the Senate Blue Ribbon Committee after Gatchalian said no hearing would be held on Thursday because the inquiry into alleged flood control anomalies had been reset.
Gatchalian said the panel was now headed by Sen. Erwin Tulfo, not Sen. Pia Cayetano.
Tulfo said the Blue Ribbon inquiry would resume on June 8.
Pia Cayetano pushed through with the hearing and presided over proceedings with 18 former Marines as resource persons. They were expected to corroborate the testimony of retired sergeant Orly Guteza.
Guteza had said that from Dec. 5, 2024, to August 2025, when he served as one of former Ako Bicol Party-list representative Zaldy Co’s security personnel, he delivered luggage containing millions of pesos in cash to former House Speaker Martin Romualdez’s residences in Pasig and Taguig at least three times.
Present at the hearing were Alan Peter Cayetano, Sen. Rodante Marcoleta, who heads the Blue Ribbon subcommittee, and Senators Imee Marcos and Robin Padilla. Sen. Loren Legarda also appeared and maintained that she remains Senate president pro tempore.
Alan Peter Cayetano administered the oath to the resource persons after Blue Ribbon Committee staff failed to attend.
What happened inside the Senate
On Thursday, tension rose inside the Senate premises after Interior Secretary Jonvic Remulla was accused of trying to block the entry of the 18 former Marines.
Remulla denied it.
“I was walking out when I was pushed aside,” he said. “How can I do that (block them)? I was alone.”
Gatchalian said he asked Remulla to go to the Senate building as a “preemptive action.”
Pia Cayetano questioned Remulla’s presence and his authority to stop a senator from entering the Senate.
She said the Senate already had a sergeant-at-arms and security personnel.
Who is affected
The dispute has already affected Senate employees, media access and committee work.
Gatchalian issued a memo allowing Senate staff to shift to work-from-home status on June 4. He also allowed employees who reported on site to leave beginning at 10 a.m. because of anticipated activities within and around the Senate premises.
The advisory said no official business had been scheduled that day and cited the “safety, security, and well-being of Senate personnel.”
During the hearing, Marcos said the proceedings were not being aired on the Senate website. Alan Peter Cayetano also said some members of the media were prevented from entering the Senate premises.
What’s next
Paredes said the conflict could affect the impeachment proceedings against Vice President Sara Duterte in the Senate because the split among senators could complicate efforts to secure the votes required for conviction.
He said he expects the prosecution panel from the House of Representatives to push for the continuation of proceedings and the presentation of evidence.
Even if the trial ends, Paredes said the public would still gain insight into the allegations and the credibility of witnesses presented during the proceedings.
The next scheduled step in the Blue Ribbon Committee inquiry is June 8, when Tulfo said the hearing would resume. / JGS, TPM