Three leading Hong Kong democracy campaigners face trial Monday over their involvement in massive rallies calling for political reform, as room for opposition in the semi-autonomous city shrinks under an assertive China.

Rights groups have urged authorities to drop what Amnesty International called the “chilling prosecution” of nine activists — the pioneering trio, lawmakers, student leaders and pro-democracy party campaigners.

Reverend Chu Yiu-ming, Benny Tai and Chan Kin-man. Photo: In-Media.

All nine face “public nuisance” charges for their participation in 2014’s Umbrella Movement protests. The charges are based on colonial-era law and carry maximum jail terms of up to seven years.

Sociology professor Chan Kin-man, 59, law professor Benny Tai, 54, and baptist minister Chu Yiu-ming, 74, founded the “Occupy Central” movement in 2013.

It called for the occupation of Hong Kong’s business district if the public was not given a fair vote for the city’s leader, who is appointed by a pro-Beijing committee.

The campaign was overtaken by a student movement that exploded in September 2014 when police fired tear gas on gathering crowds.

The Occupy trio urged people to join what became known as the Umbrella Movement as protesters used umbrellas to shield themselves from tear gas and pepper spray.

The movement failed to win reform and since then activists have been prosecuted, with some jailed.

‘Wake up the people’

Chan gave a farewell talk on Wednesday night to a full house of more than 600 people at the Chinese University of Hong Kong, where he has been teaching for over two decades.

“So long as we are not crushed by imprisonment and trial and do not become overly frustrated and angry, then we will become stronger and we can inspire many more people,” he told the audience, announcing his early retirement from next year.

Photo: inmediahk.net.

“Only in the darkest hours, we can see the stars,” Chan added.

He told AFP ahead of the trial that he had prepared for the physical and mental challenges of possible jail time by taking up marathon running.

Chu, who has been unwell but attended Chan’s talk, said the trio had “prepared to walk on this path”.

“We were always willing to be sacrificed in order to wake up the people,” Chu told AFP.

Reverend Chu Yiu-ming. File photo: In-Media.

Hong Kong has been governed under a “one country, two systems” arrangement since it was handed back to China by Britain in 1997.

It allows far greater civil liberties than on the Chinese mainland, but there are growing fears those freedoms are being eroded.

Amnesty described the case as an act of retaliation aimed at silencing the democracy movement.

Man-kei Tam, director of Amnesty International Hong Kong, warned there would be a “real danger” of more prosecutions for peaceful activism if the case was successful.

Human Rights Watch said the prosecutions raised further questions about how far authorities are trying to “politicise the courts”.

The trial at West Kowloon Magistrates’ Court is due to begin at 9:30 am (0130 GMT) and is expected to last 20 days.