Authorities in the Chinese capital will try detained veteran journalist Gao Yu behind closed doors on Friday, on charges related to state security, her lawyers said.
"This will be a closed trial, because it involves state secrets," defense lawyer Mo Shaoping said on Tuesday.
"Only the prosecutors, her lawyers, Gao Yu and the judges and court staff, as well as a few court police, will be present," he said.
Gao, 70, hired Mo, a top Chinese rights lawyer to defend her against charges of "leaking state secrets overseas" after she was detained in secret on April 24, and formally arrested on May 30.
Her arrest came as the authorities rounded up dozens of rights activists and dissidents for questioning ahead of the anniversary of the June 4, 1989 military crackdown on pro-democracy demonstrations in Beijing's Tiananmen Square.
She was later paraded on the ruling Chinese Communist Party's state television channel, where she was shown, her face blurred on screen, apparently confessing to having obtained a highly confidential document and sent it to an overseas website.
Mo will be arguing that much of the evidence brought by the prosecution is inadmissible under Chinese law, and also that Gao's actions didn't amount to a breach of state security, he told RFA in an interview on Tuesday.
"For example, Gao wasn't told about the CCTV broadcast in advance [by police]. They just edited a bit of her interview admitting her guilt," Mo said. "It was I who told her about the broadcast."
He said the entire video was suspect, as it appeared to have been carefully directed.
"The defense team yesterday decided we would submit a written application to the court for this evidence to be disregarded, in particular, the part where Gao admits to the charges," he said.
"We believe that she was under duress, with huge amounts of psychological pressure and suffering, and that she was forced to make a confession against her will," Mo added.
While article 12 of China's criminal law states that "no one who has not yet undergone trial needs to confess their guilt," the Communist Party has come under fire from international rights groups for broadcasting confessions on state television.
Mo said Gao appeared to be in relatively good health and spirits when he last met with her.
"She's looking well, on the face of it, although she did take some medication [during the meeting]," he said. "She said she would be able to get through the trial."
Gao's trial is scheduled to begin at 9:00 a.m. local time at Beijing's No. 3 Intermediate People's Court.
China's state secrets law covers a wide range of data from industrial information to death penalty statistics, and information can be designated a state secret retroactively.
In the latest in a long string of blows to freedom of expression since President Xi Jinping came to power, China's State Administration of Press, Publication, Radio, Film and Television reinforced a ban on disseminating "state secrets" last month.
"Reporters, editors and [anchors] should not disseminate state secrets in any form via any media and they should not mention such information in their private exchanges or letters," the official Xinhua news agency quoted the new directive as saying.
Media organizations must now sign nondisclosure agreements with journalists, who are also barred from disclosing secrets in personal communications or via personal blogs and social media accounts, or from passing them on to foreign news outlets.
Rights activists and journalists say the rules are based on a concept that is dangerously vague.
Chinese media organizations can only operate under a government-granted license, giving officials a huge amount of leverage over who works and publishes within the industry.
Editorial staff are given daily direction on how to respond to certain major news stories via directives and phone calls from the party's powerful but secretive propaganda department, which are themselves often leaked to overseas media.
Gao, who played an active part during the Tiananmen Square protests, was detained once before on June 3, 1989, as China's People's Liberation Army (PLA) moved tanks and troops into the heart of Beijing, putting an end to calls for greater democracy and rule of law.
She was released after 450 days but was then jailed again in November 1994 for "illegally providing state secrets to institutions outside China's borders" in connection with four articles she wrote in the Hong Kong-based Mirror Monthly magazine.
Reported by Qiao Long for RFA's Mandarin Service and Hai Nan for the Cantonese Service. Translated and written in English by Luisetta Mudie.