Sara Duterte impeachment trial begins, testing Philippines' political divide.

The impeachment trial of Vice President Sara Duterte, which begins on Monday, is set to frame the Philippines’ 2028 presidential race and deepen a schism between two storied political dynasties that has plunged the Senate into turmoil.

The outcome will not only determine whether Duterte can run for the presidency, but will also test confidence in the Southeast Asian nation’s institutions and politicians. Analysts say the key question will be whether the public sees the verdict as credible or instead driven by partisan interests.

The Philippine Senate is starting the impeachment trial of Vice President Sara Duterte in a politically volatile event unfolding against the backdrop of her bitter feud with President Ferdinand Marcos Jr.

More than 6,000 police officers, including anti-riot squads, were deployed to secure the Senate, where pro- and anti-Duterte demonstrators were expected to converge. Duterte or her lawyers may appear at the start of the trial, which will run for 92 days, according to a pretrial plan. A conviction requires the votes of at least 16 of the Senate’s 24 members.

It remains unclear how long the trial will last, with factors such as procedural disputes, the number of witnesses and the presentation of evidence likely to determine its pace. The impeachment trial of a former chief justice in 2012 lasted four months.

The first impeachment trial of a vice president centres on allegations that Duterte misused public funds, amassed unexplained wealth and threatened the lives of President Ferdinand Marcos Jr. the first lady and a former House speaker.

Duterte, the daughter of former President Rodrigo Duterte, denies wrongdoing and insists the impeachment is politically motivated. If convicted of the charges, which include amassing unexplained wealth and publicly threatening to have Marcos assassinated, Duterte may be permanently disqualified from holding public office.

Opinion polls show Duterte is a leading contender for the 2028 election, but a guilty verdict could jeopardise her presidential ambitions. A conviction would be a severe blow to her announced plan to seek the presidency in mid-2028, when Marcos ends his six-year term.

She cited the impeachment proceedings against then-President Joseph Estrada, in which a Senate vote to withhold key evidence triggered public outrage, halted the trial and fuelled mass protests that led to Estrada’s removal from office in January 2001.