Rappler CEO Maria Ressa talks to the media on the scheduled date of her arraignment in connection with a cyberlibel case at the Manila Regional Trial Court Branch 46 at the Manila City Hall on April 16, 2019. Ressa’s camp moved to file a motion for reconsideration seeking to reverse a Manila court’s denial of her plea to junk the case. George Calvelo, ABS-CBN News

MANILA - High-profile Philippine journalist Maria Ressa's libel trial opens Tuesday in a case that press freedom advocates see as government retaliation for her news site's critical reporting on President Rodrigo Duterte.

Ressa, who leads online outlet Rappler and was named a Time Magazine "Person of the Year" in 2018 for her journalism, is out on bail and faces years in prison if convicted.

This case is among a string of criminal charges that have hit Ressa and Rappler over the past year, prompting allegations that authorities are targeting her and her team for their work.

The news portal has reported extensively and often critically on Duterte's policies, including a deadly crackdown that rights groups say may be a crime against humanity.

"The message that the government is sending is very clear," Ressa told reporters in February as she posted bail after spending the night in jail over the libel case: "Be silent or you're next."

The case that opens Tuesday centers on a Rappler report from 2012 about a businessman's alleged ties to a then-judge of the nation's top court.

Government investigators initially dismissed the businessman's 2017 complaint about the article, but state prosecutors later decided to file charges.

The legal foundation of the case is a controversial "cybercrime law" aimed at online offences ranging from stalking to child pornography.

Ressa, 55, argues the law did not take effect until months after the story was published.

Government lawyers say it is effectively a new article since Rappler had updated it in 2014 to fix a typographical error.

While the plaintiff is a private citizen, like all criminal cases in the Philippines the suit is prosecuted by government lawyers.

Ressa and Rappler also face tax and corporate fraud cases.

Ressa's presence in court is not mandatory and she is not expected to attend the hearing, according to Rappler.

The libel case has drawn international attention, with Canadian Foreign Minister Chrystia Freeland and former US Secretary of State Madeleine Albright expressing concern over democratic rights.

Prominent rights lawyer Amal Clooney, who joined Ressa's legal team this month, said the case echoed a recurring theme in her work, where "journalists who expose abuses face arrest while those who commit the abuses do so with impunity".

Duterte, who denies being behind the case, has singled out Rappler for criticism, also banning it from covering his public events and forbidding government officials from talking to Rappler reporters.