The alleged group effort of some pro-Duterte senators to push for a resolution seeking de facto dismissal of Vice President Sara Duterte's impending impeachment trial cannot prosper, as it rests on unfounded assumptions and contradicts the Constitution, a constitutional law expert said Sunday.

Lawyer Domingo Cayosa, former president of the Integrated Bar of the Philippines, argued that senators unsupportive of impeachment cannot simply act on personal convictions, as this would violate constitutional provisions on impeachment procedures.

His remarks followed reports that several senators were considering filing a resolution which, if passed, would dismiss Duterte's impeachment without trial.

"Not only in the Constitution, but even in the Senate rules on impeachment and jurisprudence in the Supreme Court, there is no basis for the de facto dismissal they are pushing," Cayosa said.

Senator Imee Marcos, a Duterte ally, confirmed that various drafts of such a resolution are circulating. Senator Ronald "Bato" de la Rosa, another pro-Duterte lawmaker, also admitted plans to initiate dismissal.

Cayosa contended that senators cannot ignore constitutional provisions requiring the trial to proceed once an impeachment complaint is transmitted.

"All discretion or power of public officials should conform to the Constitution — that's the highest law of the land. Their discretion to make rules is subject to the mandate of the Constitution that when there is an impeachment complaint, they are supposed to try it, hearing it promptly, without delay," he said.

He criticized the Senate for "making lame excuses" to stall the proceedings, arguing the trial could have begun months ago if the Senate had acted promptly after receiving the articles of impeachment from the House in February.

"It is saddening that there are senators who are doubting or making up all sorts of excuses just to dribble, delay, and completely ignore the impeachment complaint. That is not allowed," Cayosa stressed.

He also agreed with fellow constitutional experts and House prosecutors that the Senate is a continuing body, and Congress' adjournment should not be used to justify further delays.

Senate President Francis "Chiz" Escudero, who has been accused of deliberately stalling the trial for political reasons, said the plenary will decide whether the impeachment trial will proceed into the 20th Congress.

However, with Duterte allies in the Senate, many speculate that the trial will be blocked before it formally begins.

Escudero further drew criticism when he moved the House prosecution’s presentation of the articles of impeachment from 2 to 11 June, citing priority legislation.

Incoming House lawmaker Leila de Lima of Mamayang Liberal, set to join the House prosecution panel, insisted that the Senate can hold extended sessions to ensure the trial proceeds.

"I disagree that the impeachment trial cannot go beyond the 20th Congress. The prevailing view is that it can go beyond because […] it is not an ordinary part of their ordinary law-making status, it is special, independent," she said.

Public backlash against the Senate’s perceived inaction has grown, with progressive groups and civil society coalitions accusing the chamber of shielding Duterte and enabling alleged wrongdoing.

Duterte faces charges of betrayal of public trust, culpable violation of the Constitution, bribery, graft and corruption, and other high crimes. The House impeached her on 5 February, with 215 lawmakers — well over the required two-thirds vote — approving seven articles of impeachment.

The Senate will need a two-thirds vote — or at least 16 out of 24 senators — to convict Duterte. If convicted, she will be permanently disqualified from holding public office, derailing her rumored bid to succeed President Marcos Jr. in 2028.

Progressive groups and organizations are set to hold a three-day protest at the Senate in Pasay City starting Monday to demand that the chamber uphold its constitutional duty and proceed with the trial. Ateneo schools also held a separate rally over the weekend.