Nine pro-democracy activists are set to go on trial next Monday in connection with their leading roles in the 2014 Umbrella Revolution protests in Hong Kong, in one of the most high-profile cases since the prosecution of Joshua Wong two years ago.

The group includes Benny Tai, Chan Kin-man, and Reverend Chu Yiu-Ming, who founded Occupy Central with Love and Peace, one of the founding groups behind the 79-day protest in 2014 known as the "Umbrella Movement" which called for universal suffrage.

Six other Umbrella Revolution leaders, including two sitting legislators, are also to stand trial.

They each face up to seven years of prison for charges related to "public nuisance," including "conspiracy to commit public nuisance," and "incitement to commit public nuisance."

Chan, Chu and Tai also face a charge of "incitement to incite public nuisance."

Tai told dpa he could not comment on the outcome of the trial but that he and the others were making preparations for possible prison time.

"I have confidence the court in Hong Kong is still independent and fair. Yet, I have prepared for the worst," he said by email. "When we proposed civil disobedience in 2013, we had accepted the possibility of being sued in the court, convicted and jailed."

Tai added that "the worst is yet to come," as he fears that Hong Kong will become more "authoritarian."

The trial comes at a particularly sensitive time in Hong Kong, with its government recently under fire for banning a political party promoting independence from China and denying a work visa to a foreign journalist.

The continued prosecution of Umbrella Movement leaders has also been criticized by human rights groups including Amnesty International, which said last week the trials were having a "chilling effect on freedom of peaceful assembly and expression" in the semi-autonomous Chinese city.

"I would say that it is just a tipping point for the world to see the condition of the rule of law [in Hong Kong]," Joshua Wong told dpa.

"I think [they will now be] aware political prosecution is not only towards youngsters but also includes professors, lawyers, or legislators or activists from different backgrounds and it's cross-generation suppression [directed] towards Hong Kong's pro-democratic camp."

Chan, Chu, and Tai originally proposed to protest in 2013 in case Beijing failed to grant universal suffrage in the election of Hong Kong's top leader.

Thousands of protesters took to the streets for 79 days in 2014 when it became clear that only candidates vetted by Beijing would be allowed to run for chief executive.

In the years since the protests failed, many politically active young Hong Kongers have moved towards more localist and pro-independence political views, which were almost unheard of prior to 2014.

Chan told dpa he predicted such a fallout if the protests failed and other "serious consequences" when he first called for them in 2013. 

"I am very pessimistic in the future of Hong Kong... [It] is already a very mature society for democracy. We have a large middle class, we are very educated society, we already have political parties, we have a vibrant civil society," he said.

"The political system lags behind our society so naturally it will have lots of conflict [and] grievances."