MANILA (Reuters) - A news website bitterly opposed by Philippine President Rodrigo Duterte on Thursday petitioned the Supreme Court to overturn a ban on coverage of his events, calling it an unconstitutional assault on the freedom of press.

Rappler CEO and Executive Editor Maria Ressa steps out with her lawyer Eric Recalde after being arraigned at the Court of Tax Appeals in Quezon City, Philippines, April 3, 2019. REUTERS/Eloisa Lopez

Rappler, a media startup known for its tough investigative reporting of one of Asia’s most volatile leaders, is the subject of numerous legal challenges backed by government lawyers that cover tax evasion, libel, and ownership violations.

It has long complained that a ban backed by no known written order was widely enforced by presidential staff to block its reporters from important public events, setting a bad precedent for a country long seen as Southeast Asia’s standard-bearer of media freedom.

“This case is not just about Rappler,” the startup said in a statement. “It is about every journalist’s mandate to cover without prior restraint or threat of punishment the office of the president and scrutinize the tremendous power it holds.”

Rappler’s award-winning head and co-founder, Maria Ressa, has been charged in 11 legal cases, all of which she says are part of a coordinated campaign of legal harassment and online trolling intended to deter journalists from scrutiny of the popular 74-year-old Duterte.

The government says Rappler is being pursued for breaking the law, and not for its brand of reporting.

Duterte, a maverick former mayor known as “the punisher” for his zero-tolerance approach to crime, drugs and graft, denies trying to stifle Rappler but has no qualms about accusing it of fabricating stories and being a tool of the U.S. Central Intelligence Agency.

Rappler dismissed that. In its 75-page filing to the Supreme Court, it quoted some of Duterte’s expletive-laden tirades against it and challenged the legality of an order that, like many of the president’s most controversial policies, was only a verbal instruction.

“The prohibition is based on a personal determination by the executive branch that Rappler or its journalists are ‘liars’ or peddlers of ‘fake news’, a determination which has no basis in law,” it said.

Asked about the petition, Duterte’s spokesman, Salvador Panelo, said, “It’s a free country. We do not interfere with the judiciary.”