Lee Cheuk-yan, Chow Hang-tung and Albert Ho are accused of inciting subversion of state power, as is the alliance itself.
For years, the group organised June 4 vigils at Victoria Park to remember the events of 1989 in Beijing and other mainland cities.
Prosecutors allege the defendants incited others to organise, plan, commit or participate in acts by unlawful means with a view to subverting state power between July 1 last year and September 8 this year – including to overthrow China’s basic system or body of central power.
Chow said the alliance had been unable to hold a meeting to decide who should represent the group in court being as seven of its core members were being held in custody.
The magistrate accepted the prosecution’s request to adjourn the case to October 28, to allow more time for the police to conduct an investigation, including examining USB drives, laptops and computers seized from the alliance’s office.
Chow’s application for bail was rejected. Lee and Ho were already behind bars in relation to other cases.