Judge Victor So in the West Kowloon Court ruled the defendants will return to court on Sept. 23 after Thursday's appearance as prosecutors had requested more time to prepare the case.
The 47, most of whom have been denied bail, were arrested on charges of participating in an unofficial, non-binding and independently organised primary vote last year to select candidates for a since-postponed city election, which authorities say was a "vicious plot" to subvert the government.
The charges against the activists, many of whom have announced their retirement from politics, are punishable with up to life in prison.
Diplomats and rights groups are closely watching the case amid mounting concerns over the independence of the former British colony's judicial system, which is seen as the foundation on which its financial prowess was built.
Authorities have repeatedly said the judiciary was independent and upholding the rule of law. They have said prosecutions were independent, based on evidence and had no relation with the background or profession of the arrestees.
Marathon bail hearings in March lasted four days and dragged late into the night, causing several defendants to fall ill and seek hospital treatment. Most of the subsequent appeals for bail have been denied.
The security law sets a high threshold for defendants seeking bail to demonstrate they would not break the law, a departure from common law practice, which puts the onus on prosecutors to make their case for detention.
Reasons for denying bail included unanswered emails from the U.S. Consulate and WhatsApp messages with foreign journalists.
The protracted hearings and the reasons for rejecting bail have stunned diplomats and rights groups, who see it as a dramatic display of the Chinese-ruled city's authoritarian turn.
More than 120 people have been arrested under the security law so far, mostly opposition politicians, democracy activists and students as young as 15. (Reuters)