The judicial authorities plan to put another female activist on trial following the ten-year jail term imposed on the blogger known as Mother Mushroom last month.
Tran Thi Nga, a campaigner for women’s rights and democratic freedoms, will face trial later this month on charges of conducting propaganda against the state.
The People’s Court of Ha Nam province in the Red River Delta said the trial would begin on July 25.
Nga has been held in detention since her arrest at her home in the northern province on the eve of the Tet holiday in January.
She faces the same charge, under Article 88 of the penal code, as that brought against the blogger, Nguyen Ngoc Nhu Quynh, who was given the unusually harsh ten-year sentence in June.
Ms Nga first drew attention for her campaigns on behalf of Vietnamese migrant workers in Taiwan. She later took part in protests against Chinese expansion in the South China Sea and against the Formosa steel plant.
A toxic leak from the plant caused a major environmental disaster off the north-central coast last year.
The authorities have taken an increasingly hard line against activists involved in the environmental campaign. The Communist leadership appears concerned that popular discontent over its handling of the disaster could undermine government authority.
Ms Nga’s lawyers were allowed to meet her last month for the first time since her arrest.
One was quoted as saying that she was in poor health because of an injury sustained during an earlier assault by police and their proxies.
Ms Nga, like many civil society activists, had suffered a sustained campaign of violence and intimidation before her arrest.