Hong Kong marks Tiananmen massacre for what many fear will be the last time - CNN

Every year since then, Lee has helped organize a candlelit rally in Hong Kong to mark the anniversary, the only mass memorial held on Chinese soil and a key emblem of the semi-autonomous city's political freedoms.

Last month, China announced that it would impose a national security law on Hong Kong, in response to widespread and often violent anti-government unrest last year.

It also permits Chinese security services to operate in Hong Kong for the first time -- leading to fears among many in the city that members of the PLA could be deployed onto the streets should protests resume.

The Hong Kong Alliance in Support of Patriotic Democratic Movements in China, the group co-founded by Lee which has organized the Tiananmen vigil every year since 1990, has warned that it could be banned under the new law, pointing to its previous support of activists convicted under similar national security laws in China and a longstanding opposition to "one party dictatorship."

There is good reason to believe the vigil may be banned in future.

Some 500 people were extracted from China, according to the Hong Kong Alliance, including student protest leaders such as Wu'er Kaixi, who famously debated Chinese Premier Li Peng at the height of the demonstrations.

In the years after the crackdown, pressure grew on the British to do more to protect Hong Kong under imminent Chinese rule, and in 1994 then Governor Chris Patten made elections to the city's parliament fully democratic for the first time -- a move that was not approved by London and met with outrage in Beijing.

Smaller gatherings will be held across the city, and the Alliance has called on all residents to light candles at 8 p.m., holding them outside their windows to recreate the sea of light that has become a common image of the annual vigil at Victoria Park.

"Will Hong Kongers be able to hold the vigil next year?

"Yet, unless there is an unexpected change in leadership in Beijing, it surely seems likely, especially in light of the forthcoming (national security law), that Hong Kong might follow Macao in succumbing to the amnesia that has long been forced upon the mainland."