The official prohibition came on Monday, as Hong Kong recorded three new local coronavirus infections, raising the total to five in just two days after more than two weeks without a locally transmitted case.

In the letter of objection, police cited the prohibition against public gatherings of more than eight people, which was earlier extended to June 4, and said any large public assemblies would increase infection risks for the public.

Veteran pan-democrat Lee Cheuk-yan, who chairs the alliance, previously called the government’s extension of the restriction on gatherings a political one, pointing out it was in the process of reopening schools and allowing larger religious gatherings.

Speaking at a press conference following Monday’s decision, Lee said the police were simply using the virus as a pretext to do something they already intended to do.

“This year, on the 31st anniversary [of Tiananmen Square], without even having the national security law in place, [the vigil] was banned by the police in the name of the virus,” said Lee, who wore a black mask that read “freedom of speech”.

Tiananmen vigil organiser urges would-be participants to ‘be water’ if event banned

“We believe this is totally unreasonable and unscientific, because everything is normal in Hong Kong. They are just using this excuse to suppress our rally,” he added, pointing out that schools, karaoke lounges and sports facilities had already reopened.

Lee also said whether the annual vigil was allowed served as a “litmus test” for the “one country, two systems” principle.

“If they suppress us, it means that one country, two systems is no more,” he said.

“By banning us this year and banning us maybe in the future, they are telling the world what the people of Hong Kong have been worrying about all these years. ‘When are they are going to ban the June 4 candlelight vigil?’ … They are doing it now. With the national security act, we cannot be optimistic.”

The vigil, where calls for an end to “one-party dictatorship” have been routinely heard, is under a fresh spotlight this year as Beijing moves forward with a tailor-made national security law for Hong Kong. The law will prohibit acts of subversion, secession, terrorism or conspiring with foreign influences in the city.

Pro-establishment heavyweight Maria Tam Wai-chu, a Basic Law committee member, on Monday morning said she would advise participants at future rallies to err on the side of caution and leave if people started shouting slogans referencing “one-party dictatorship”.

“You have to make a decision. If that is not your goal, you should walk away,” Tam told a local radio programme, adding that the police would primarily target those who both “chanted slogans as well as took actions”.

Hong Kong keeps Tiananmen memory alive with ‘record-breaking’ mass vigil

She also added there was no such dictatorship as the mainland has multiple political parties, calling the slogan itself as a “false proposition”.

Lee, the vigil organiser, said while he was worried about the law, he would not stop chanting the slogan.

“With the national security act coming in, of course, we are even more worried about what [will] happen next year,” he said.

“National People’s Congress members have begun to say our slogan, ‘end of one-party rule’, is not allowed and may be an offence. But we have been shouting that slogan for over 30 years. We will continue, come what may. Let’s see if our space in Hong Kong will be far less than [in] the past.”

Because of the police ban, Lee said the rally would be held online and spread out across different districts. He encouraged people in Hong Kong to join as individuals without breaching the gathering bans while gaining international support.