Vice President Sara Duterte's lawyers said on Monday prosecutors would first need the Senate impeachment court's approval if they intended to treat her chief of staff, Zuleika Lopez, as a hostile witness.

House private prosecutor Atty. Jay Tolosa earlier said Lopez's testimony would be crucial because she was present when Duterte allegedly made the verbal threats that underpin the first article of impeachment, giving her firsthand knowledge of events central to the prosecution's case.

"That is something the prosecution will have to work on in their presentation. They will have to have the witness qualify as a hostile witness," defense spokesperson Michael Poa said ahead of Lopez's testimony.

However, Clerk of Court Renato Bantug Jr. said the manner in which Lopez would be presented remained the prosecution's decision, including whether it would ask the impeachment court to treat her as an adverse witness.

Under Philippine rules of evidence, an adverse witness is one identified with the opposing party and may be asked leading questions by the party calling the witness. 

A hostile witness, meanwhile, must first be declared hostile by the court after showing hostility or unwillingness to testify, allowing broader questioning by the party that presented the witness.

The House prosecution panel last week laid the foundation of its case by presenting documentary evidence and video recordings, including Duterte's November 2024 remarks in which she said she had instructed someone to kill President Ferdinand Marcos Jr., First Lady Liza Araneta-Marcos and then-House Speaker Martin Romualdez if she herself were assassinated. 

Once running mates whose tandem delivered one of the country's biggest electoral victories, Marcos and Duterte have since become political rivals, with disputes over policy, power and governance culminating in the second impeachment of the incumbent Vice President by the House of Representatives earlier this year.

Conviction requires the votes of at least 16 of the Senate's 24 members and would remove Duterte from office while permanently disqualifying her from holding public office, effectively ending any bid for the presidency in 2028.

Separately, Poa sought to clarify Duterte's statement last week—"In this bloodbath and bludgeoning, I will be bloodied but unbowed"—had been widely misunderstood.

"What she meant by the bloodbath was actually herself. It was subject to a lot of misinterpretation, which is understandable. But I think the Vice President has already clarified that," Poa told defense impeachment reporters.

House prosecution spokesperson Lanao del Sur Rep. Zia Alonto Adiong said the impeachment proceedings were intended to establish accountability, not to inflict harm to the incumbent Vice President, adding that he did not understand the defense's repeated references to blood.

Duterte’s statement echoed William Ernest Henley's poem Invictus, whose closing line — "My head is bloody, but unbowed" — has become a recurring motif in the Duterte family's public messaging during legal crises. 

Her younger sister, Veronica Duterte, quoted the same poem in April during an International Criminal Court visit to their father, former President Rodrigo Duterte, portraying him as defiant despite his detention in The Hague.

Poa also declined to rule out another surprise appearance by Duterte at the Senate.

"As of now, she hasn't mentioned anything to me," he said. "But of course, I wouldn't discount the possibility."