Senate trial outcome could permanently bar Duterte from office, shaking her frontrunner status for the 2028 election.

The impeachment trial of Philippine Vice President Sara Duterte has begun in Manila, in a highly charged case that could determine her political future.

Thousands of police were deployed around the Senate in the capital on Monday as protesters calling for Duterte’s conviction began gathering outside. The vice president’s office said she would not appear in person.

The House of Representatives impeached the daughter of former President Rodrigo Duterte on allegations of corruption, bribery and an assassination plot against one-time ally President Ferdinand Marcos. Duterte denies wrongdoing.

“We, her lawyers, are here … to prove the allegations against her have no basis,” Michael Poa of Duterte’s defence team told reporters.

In a statement, Duterte said the decision to “appear through counsel rather than testify personally does not diminish accountability or imply a lack of transparency”.

Second impeachment complaint

The outcome of the trial, which could last several months, may determine whether Duterte will be barred from running for president in the 2028 election.

Only a guilty verdict by two-thirds of the bitterly divided 24-seat Senate can strip her of the vice presidency and permanently bar her from elected office.

Duterte remains a presidential frontrunner for 2028, with a late May survey suggesting 51 percent of respondents planned to vote for her.

Reporting from Manila, Al Jazeera’s Barnaby Lo said less than two years into the Marcos administration, the House of Representatives – then led by a cousin of the president – began investigating the vice president for alleged corruption.

“The probe snowballed into the first impeachment complaint … which was voided by the Supreme Court,” he said. “But here we are now, with Duterte facing a second impeachment complaint.”

Duterte and Marcos are heirs to two of the country’s most powerful political dynasties.

In 2022, they won an election on a joint ticket, but their alliance has since collapsed in an increasingly bitter feud that deepened after ⁠Rodrigo Duterte’s arrest and transfer to International Criminal Court (ICC) custody last year on murder charges linked to his so-called “war on drugs”.

The bitter fight has spilled into the Senate, raising questions about how the trial will unfold.

In a dramatic turn on Monday, Duterte’s ally Senator Rodante Marcoleta was arrested on a plunder charge shortly before the start of the trial, throwing support for the vice president in the Senate into doubt.

In May, just as the Senate was preparing to receive the impeachment complaint from the House of ⁠Representatives, Duterte ally Senator Ronald “Bato” dela Rosa turned up in the chamber after being absent from public view ⁠since November and cast the decisive vote to install Alan Peter Cayetano as Senate president.

Dela Rosa then holed up in the Senate before slipping away early on May 14, hours after chaos and gunfire erupted in the parliament building. His whereabouts are unknown. Cayetano was the running mate of Duterte’s father in the 2016 election.

Dela Rosa, who also faces ICC charges, was national police chief during much of the drug crackdown, in which thousands of suspects were killed. He and Rodrigo Duterte have denied wrongdoing.

About a month later, senators aligned with a rival bloc secured enough support to elect Senator Sherwin Gatchalian as Senate president.