Three of Hong Kong's most prominent democracy activists have been sentenced to between five and seven years in prison for their role in the organisation that spent decades keeping the memory of China's 1989 Tiananmen Square crackdown alive.

A Hong Kong court on Friday sentenced Chow Hang-tung to seven years and three months in prison and veteran activist Lee Cheuk-yan to seven years after they were convicted of inciting subversion under the national security law imposed by Beijing in 2020. Albert Ho, another former leader of the organisation, received five years and two months after pleading guilty. Lee and Chow, who pleaded not guilty, plan to appeal.

All three were leaders of the now-dissolved Hong Kong Alliance in Support of Patriotic Democratic Movements of China. For more than 30 years, the Alliance organised an annual candlelight vigil at Victoria Park commemorating those killed when Chinese troops crushed pro-democracy demonstrations centred on Beijing's Tiananmen Square in June 1989. The crackdown killed hundreds and possibly thousands of people. In mainland China, public discussion and commemoration of Tiananmen remain heavily restricted. Hong Kong was once the major exception.

The Victoria Park gathering became one of the most visible symbols of the political freedoms that distinguished Hong Kong from mainland China after the former British colony returned to Chinese rule in 1997. Tens of thousands regularly attended, and in some years participation exceeded 100,000. The vigil was first banned in 2020 during the COVID-19 pandemic and has not returned since Beijing imposed the national security law that year following the massive anti-government protests of 2019.

The prosecution centred not simply on commemorating Tiananmen, but on the Alliance's longstanding political demand to “end one-party dictatorship”. Prosecutors argued that Communist Party leadership is protected by China's constitutional order and that the slogan represented an attempt to undermine state power. The judges accepted that argument. Significantly, they acknowledged that the case involved neither violence nor threats of violence and that the Alliance had not laid out a specific method or timetable for achieving its political demand. Nevertheless, the court concluded that the defendants continued promoting the cause despite knowing that it could violate the national security law.

Lee and Chow rejected the prosecution's interpretation. Lee argued during the trial that calling for democratic reform did not come from hostility towards China. Chow, a Cambridge-educated lawyer who represented herself, maintained that advocating democracy should not constitute a crime. She has spent much of the period since 2021 behind bars and has staged hunger strikes around the anniversary of the Tiananmen crackdown.

Hong Kong authorities strongly defend the prosecution. Chief Executive John Lee said the defendants had gone beyond the lawful exercise of freedom of expression, while national security police described the proceedings as fair, impartial and transparent. Beijing and Hong Kong's government maintain that the security law restored stability after the turmoil of 2019 and that political freedoms cannot be used to threaten national security.

Critics see something very different. Taiwan condemned the sentences as political persecution, while the European Union has said the Alliance case demonstrates the continuing deterioration of freedom of expression, assembly and independent civil society in Hong Kong.

The larger significance goes beyond the prison terms. For decades, Hong Kong was the Chinese city where tens of thousands of people could gather openly with candles to remember June 4, 1989. The vigil survived the handover to China, political controversies and repeated demands from Beijing for greater patriotism.

It did not survive the national security era.

The people who organised it are now in prison, the organisation itself has been dissolved, and the public commemoration that once filled Victoria Park has disappeared. Thirty-seven years after Tiananmen, remembering it publicly in Hong Kong has become far more dangerous than it once was.