Watching proceedings in court was Victoire Ingabire, another woman who sought to run for the presidency in 2010, but was blocked from competing, arrested, tried and spent six years in jail before her release in September.
Prosecutors on Wednesday requested that Rwanda's leading dissident politician be handed 22 years in prison for inciting insurrection and forgery as her trial opened in the capital Kigali.
"We request that Diane Rwigara be imprisoned for 15 years for inciting insurrection and seven years for forging documents," prosecutors told the single-day hearing at Kigali's High Court.
But a treason charge, which had previously been laid against Rwigara, was not mentioned in court.
Rwigara, 37, denies the charges, dismissing them as "politically motivated" after her blocked attempt to challenge President Paul Kagame in last year's elections.
She appeared in court on Wednesday alongside her mother who prosecutors also want sentenced for 22 years for inciting insurrection and promoting sectarianism in a country still overshadowed by the 1994 genocide.
The two women had spent more than a year behind bars before being released on bail last month ahead of their trial.