Manila: Philippine Senators, led by Alan Peter Cayetano, took their oath Monday as the Senate formally convened as an impeachment court for the trial of Vice President (VP) Sara Duterte in a historic political showdown that could reshape the country’s leadership ahead of the 2028 elections.
Wearing traditional judicial robes, senators gathered at the Senate session hall in Pasay City to swear an oath to serve as senator-judges in proceedings stemming from impeachment complaints endorsed by the House of Representatives earlier this year.
Impeachment complaint
In the article of impeachment filed by the House following a 257-25 vote, VP Duterte faces allegations involving the misuse of confidential and intelligence funds, unexplained wealth and public remarks directed against President Ferdinand Marcos Jr., First Lady Liza Araneta-Marcos and former House Speaker Martin Romualdez.
House prosecutors accuse Duterte of violating constitutional provisions on public accountability and betraying public trust, charges the vice president has repeatedly denied.
Her allies have described the impeachment effort as politically motivated and tied to widening divisions between the Marcos and Duterte camps, once allies during the 2022 national elections.
Opisyal na tayong nag-convene sa Senado bilang impeachment court. pic.twitter.com/DD7CIEIzfL
— Win Gatchalian (@WinGatchalian74) May 18, 2026
Start of process
The Senate’s convening as an impeachment court marks the start of a process expected to include the presentation of evidence, witness testimonies and legal arguments from both the prosecution and defense panels.
Under the 1987 Philippine Constitution, a two-thirds vote of the Senate is required to convict and remove an impeached official from office.
Outside the Senate complex, protesters and supporters from both camps gathered under heavy police presence, reflecting deepening political tensions across the country.
Analysts said the proceedings could test the stability of the Marcos administration and further define the balance of power among the nation’s most influential political families.
The impeachment trial is expected to run for several weeks.
Senators have yet to finalise a full calendar for hearings and procedural motions. Duterte remains vice president while the trial is ongoing.
At 5 pm on Monday, the 11 members of the House prosecution panel formally filed their “Entry of Appearance” at the Senate in Pasay City, Manila. The Upper House is serving as the Impeachment Court for the upcoming trial of Vice President Sara Duterte. House Secretary General Cheloy Garafil personally submitted the document on behalf of the prosecutors elected by the House.
What to expect
Key developments and scenarios to expect as the impeachment trial of VP Sara Duterte moves forward in the Philippine Senate:
Opening procedural battles
The first phase will likely focus less on evidence and more on legal and procedural process, including:
challenges to the impeachment complaint’s validity,
disputes over Senate rules,
questions about jurisdiction,
and motions from Duterte’s defence team seeking dismissal or delays.
Lawyers on both sides are expected to argue over whether the articles of impeachment meet constitutional standards and whether the House followed proper procedures before transmitting the case to the Senate.
Presentation of evidence
If the trial proceeds fully, House prosecutors are expected to present:
audit records,
budget and disbursement documents,
testimony from government officials,
and evidence related to confidential and intelligence fund expenditures.
The prosecution may also attempt to establish patterns involving alleged unexplained wealth and statements they claim threatened or undermined top government officials, including President Ferdinand Marcos Jr..
Duterte’s defense is expected to argue:
the confidential funds were legally used,
no criminal misuse has been proven,
and the impeachment effort is politically motivated.
For the fourth time in Philippine history, the Senate convenes as an impeachment court. Unless Senator Bato Dela Rosa surfaces again, 23 Senator-Judges will decide whether VP Sara Duterte will be removed from her office and be perpetually disqualified from public office. 2/3 of… pic.twitter.com/HOyxLGYniM
— Cleve V. Arguelles (@CleveArguelles) May 18, 2026
Major political pressure on senators
The trial will place intense pressure on senators acting as judges.
Many senators are widely seen as weighing:
public opinion,
alliances with the Marcos administration,
relations with the Duterte political bloc,
and their own 2028 political ambitions.
Because a two-thirds Senate vote is required for conviction, every major alliance shift will be closely watched.
