MANILA - It is "absolutely necessary" for Malacañang to prove the veracity of an "Oust-Duterte" matrix it revealed to reporters last week, contrary to the claim of the presidential spokesperson, the leader of a lawyers' group named therein said Thursday.

Presidential Spokesman Salvador Panelo said the matrix, which linked lawyers and journalists to an alleged ouster plot against President Rodrigo Duterte, only shows the existence of an alleged plan, which cannot be considered a crime yet.

• No need for Duterte to prove ouster matrix - Malacañang

It is "astonishing and even atrocious" for lawyers to say that they are "not obligated" to support a "contrived conspiracy" they passed off, said Edre Olalia, president of the National Union of Peoples' Lawyers.

"By any standard, that is unfair. It doesn’t even come close to the basic rules of evidence, basic rules of fair play and due process," he told ANC's Early Edition.

The group of pro-bono lawyers has sought a writ of amparo and writ of habeas data for its members and filed the matrix as a supplemental manifestation before the Supreme Court to justify its plea for protection from alleged harassment by government forces.

"This is another proof that the demonization, the criminalization of our profession is ongoing," Olalia said.

He added, the group could also press Malacañang to present evidence, “otherwise, you have to put up or shut up because you cannot just go around, spreading all these lies."

"They’re saying no, you just have to believe the President. But that entails a lot of inordinate generosity to give so much trust to somebody who has been known to have planted evidence when he was a prosecutor or we have known to have given different figures when it comes to the drug war," he said.

The release and publication of the matrix have "great implications" not only to the members of NUPL, whose top officers were tagged, but to critics and dissenters as well, said Olalia.

"The message being sent is very clear: you will be threatened, you will be harassed, you will be intimidated, you will be discredited, and even discouraged from doing your work," he said.

Apart from the NUPL, media organizations Vera Files, Philippine Center for Investigative Journalism and Rappler, which have been critical of the administration, have also been named in the matrix.

• Malacañang claims journalists, lawyers behind ‘Oust Duterte’ plot