As the Senate opened the impeachment trial against Vice President Sara Duterte on Monday, the country's second highest official fired back at President Ferdinand Marcos Jr., declaring that a president's personal views have no place in proceedings that must be decided solely by the Constitution and the rule of law.

In a statement issued shortly before the Senate convened as an impeachment court, Duterte rejected suggestions that she should personally take the witness stand, saying the question of whether an impeached official appears in person or through legal counsel is a matter of constitutional right—not public expectation.

"The opinion of a President in an impeachment proceeding is of no importance," Duterte said.

"Impeachment proceedings must be guided by the Constitution and due process. The respondent has the right to be represented by counsel, and the decision to personally testify is a matter of legal strategy and constitutional rights."

Marcos over the weekend said he would "almost insist" on personally appearing before an impeachment court if he were in Duterte's position—even against the advice of his lawyers.

"It would be much easier to get to the bottom of everything if you can speak to the accused directly," Marcos said, while emphasizing that he was merely expressing a personal opinion and not a legal one. 

Duterte, however, argued that the success or failure of an impeachment case does not hinge on whether the respondent takes the stand.

"The burden remains on the prosecution to prove its case. Choosing to appear through counsel rather than testify personally does not diminish accountability or imply a lack of transparency. The integrity of an impeachment trial depends on adherence to the rule of law—not on whether the respondent personally takes the stand," she said.

Under the Senate Rules on Impeachment, a respondent may appear either personally or through counsel, leaving the decision to the defense panel. 

Duterte's lawyers had previously indicated that whether she would personally attend would depend on developments during the proceedings. 

The vice president likewise called on public officials to avoid injecting personal opinions into matters pending before constitutional bodies.

"At all times, public officials are best served by keeping their personal opinions to themselves and relying instead on the law, established policies, scientific evidence, and objective facts when addressing matters of public concern," she said.

Marcos and Duterte, whose once-formidable UniTeam alliance has collapsed into one of the country's most consequential political rivalries. What began as a falling out over policy differences has escalated into an impeachment trial that could determine not only Duterte's political future but also reshape the race for the presidency in 2028. 

Proceedings on the opening day were expected to focus on procedural matters, including the appearance of the parties and preliminary motions, before the presentation of evidence and witnesses in the succeeding days, impeachment prosecution panel adviser former Rep. Robert Ace Barbers said on Sunday.

Duterte faces four articles of impeachment accusing her of culpable violation of the Constitution, betrayal of public trust, graft and corruption, and other high crimes. 

The allegations include the alleged misuse of P612.5 million confidential funds, unexplained wealth, bribery involving officials of the Department of Education, and public statements interpreted as threats against Marcos, First Lady Liza Araneta-Marcos and former House Speaker Martin Romualdez. 

Duterte has repeatedly denied all accusations, maintaining that the impeachment case is politically motivated. 

The trial is expected to last 92 trial days and requires the concurrence of at least 16 of the Senate's 24 members for conviction.

A guilty verdict would remove Duterte from office and permanently disqualify her from holding any public office, potentially ending what political observers have viewed as a leading bid for the presidency in 2028.