Lawyers supporting Philippine Vice-President Sara Duterte filed the first legal challenge against her impeachment at the Supreme Court on Tuesday, saying it had been unconstitutionally rushed through without proper oversight.
Duterte, onetime ally of President Ferdinand Marcos, is facing a Senate trial on charges of "violation of the constitution, betrayal of public trust, graft and corruption and other high crimes".
Among the crimes outlined is an alleged assassination plot against Marcos.
Tuesday's filing seeks to toss the impeachment and prevent the Senate from proceeding with a trial, citing the lack of time devoted to its evaluation in the House of Representatives, where it was introduced and passed the same day.
"There was no proper deliberation. There was no proper discussion," lawyer Israelito Torreon, one of 29 petitioners, said outside a venue near the court.
"The VP was not even summoned to answer for the alleged allegations ... so there was no due process at all."
He added that Duterte had "nothing to do" with the filing while rejecting the notion it represented "last ditch legal gymnastics".
"This is a legitimate attempt on the part of the people in order to stop a constitutionally void .. impeachment complaint," he said.
The battle between the Marcos and Duterte dynasties has dominated early campaigning for the May mid-term elections, when a dozen Senate seats that could determine the makeup of the vice-president's tribunal are up for grabs.
Political analyst Richard Heydarian called Tuesday's filing an attempt "to buy time and momentum".
"It's a sign they are not fully confident with surviving a prospective Senate trial," he said.
Duterte has insisted that the assassination charge, stemming from an expletive-laden broadcast in which she claimed to have instructed a man to kill Marcos were she to be killed first, was simply venting frustration with the administration.
Threats of physical violence against political opponents -- often dismissed as jest -- featured regularly during the presidency of her father, Rodrigo Duterte, who has found himself in hot water after his first speech of the campaign season.
Speaking at a rally last week, the former president suggested a bomb might be the most effective way to clear seats for his party's slate in the coming election.
"What should we do now? Let's just kill the sitting senators so their seats become vacant. If we kill 15 senators we'll all get in," he told a crowd in capital Manila.
On Monday, the Philippine National Police filed a complaint with the Justice Department, saying Duterte's comments represented "incitement to sedition".
In addition to a dozen Senate seats, more than 18,000 positions ranging from congressperson to provincial-level posts, will be decided on May 18.
The race is widely expected to set the stage for the 2028 presidential election.
