The Philippine Supreme Court voted on Friday to expel its chief justice in a vote that activists said signals "the death of democracy" in the Southeast Asian country. The move comes after President Rodrigo Duterte called her an "enemy" for confronting his administration.
She has been accused of failing to pay about two million pesos (£29,500) in taxes as well as falsifying and tampering with court resolutions.
"Even if the Chief Justice has failed our expectations, quo warranto, as a process to oust an impeachable officer and a sitting member of the Supreme Court is a legal abomination", Marvic Leonen said in his dissenting opinion.
Some senators, however, have already expressed doubt that the House of Representatives will transmit to the Senate the grounds for Sereno's supposed impeachment after the SC, voting 8-6, granted the quo warranto petition.
"During the time of PNoy (President Benigno Aquino) pa", he stressed.
Police say about 1,800 protesters gathered by midmorning to help Sereno exterior the court docket in Manila the place anti-riot policemen blocked an entry street with vans and iron railings to keep up order.
"You can not issue a quo warranto to remove an impeachable official and the system that judges you should not be the one who accuses you".
Respondent Maria Lourdes P.A. Sereno is found disqualified from and his hereby adjudged guilty of unlawfully holding and exercising the office of the Chief Justice.
Sereno returned to the Supreme Court, ending her month-long wellness leave.
TRT World spoke Ana Santos in Manila.
"This is more than a wake-up call".
Government critics say the sacking of Sereno poses a grave threat to the nation's democracy, and is part of a wider campaign by Duterte to destroy anyone he perceives as a foe, and create "one-man rule" in the Philippines.
The Philippines has on paper an independent judiciary which is meant to be a check and balance on executive power.
Sereno said there must be a "strong force" that compelled the magistrates to vote as they did. "Duterte will be a virtual dictator so the institutions should really wake up".
Critics warned the court action would set a unsafe precedent and give the Duterte administration a legal weapon to muzzle dissent.
"The Supreme Court, a co-equal branch of government, is duty-bound to uphold the Constitution". Pangilinan also said Sereno should appeal the decision.
Duterte has sought the removal of Sereno and a top anti-graft prosecutor, Conchita Carpio-Morales, accusing them of allowing themselves to be used to discredit his administration.
Duterte said he had avoided getting involved in efforts to remove Sereno but got fed up.
The powerful Committee on Justice in the House of Representatives earlier recommended the impeachment of Sereno after several hearings for alleged unexplained wealth and betrayal of public trust, among others.
Meanwhile, 130 law deans and professors from various law schools in the country have issued a last-minute appeal for the Court to reject the quo warranto petition and instead pushed for the trial of Sereno before an impeachment court.
Sereno told the crowd: "Let's continue to defend the constitution and fight wrongdoing".
Global rights groups and local critics have accused Duterte of drifting toward authoritarianism after declaring martial law in the south amid a major attack by pro-Daesh militants previous year.