House Lead Public Prosecutor Gerville Luistro on Monday urged the Senate to resolve its leadership dispute before the impeachment trial of Vice President Sara Duterte begins, warning that the controversy could trigger another constitutional challenge and delay the proceedings.

Luistro said her concern stems from the Supreme Court's ruling declaring Duterte's impeachment by the 19th Congress unconstitutional, stressing that questions over the legitimacy of the Senate presidency could complicate the process once again.

“We are apprehensive that we might encounter another constitutional issue because we will be starting the trial and there is no duly elected Senate President,” she said.

The lawmaker clarified that the House of Representatives is not taking sides in the leadership contest and will respect whoever the senators elect to lead the chamber.

“If it is Acting Senate President Win Gatchalian, we will welcome that. If it will be someone else, we will welcome that because that is the judgment and prerogative of the members of the Senate,” Luistro said.

She added, however, that the House and the prosecution panel currently recognize Acting Senate President Sherwin “Win” Gatchalian as the Senate's leader.

Asked whether the impeachment court should be presided over by a lawyer, Luistro said legal credentials are not a requirement since impeachment is a unique constitutional process.

“Let us remember that the impeachment trial is not purely a legal process. It is sui generis. In one way, it is constitutional. In another way, it is administrative. And in another way as well, it is legal,” she said.

Luistro emphasized that impeachment is intended to determine whether a public official remains fit to hold office rather than establish criminal or civil liability.

“Remember that what we are testing here is the fitness of the public official to continue holding office and not the criminal liability, not the civil liability,” she said.

President Ferdinand Marcos Jr. has called Congress into a special session on 17 June to tackle priority legislation that remained pending before the adjournment of regular sessions. The session is also expected to provide the Senate an opportunity to formally address its leadership impasse.