Disqualified candidates included activist Joshua Wong, some members of the Civic Party and others who won an unofficial primary vote held by the opposition camp earlier this month.
At least 12 Hong Kong opposition nominees including prominent activist Joshua Wong have been disqualified for September legislative elections.
Others who were disqualified include democracy activist Tiffany Yuen from the disbanded political organisation Demosisto, as well as incumbent lawmaker Dennis Kwok and three others from the Civic Party, with authorities saying on Thursday the candidates failed to uphold the city's mini-constitution and pledge allegiance to Hong Kong and Beijing.
It marks a setback for the anti-China camp, which had aimed to win a majority of seats in the legislature this year.
Many of those disqualified took to social media to post the letters confirming they had been barred – including Wong, one of the city's best-known activists.
"Beijing shows a total disregard for the will of the Hongkongers, tramples upon the city's ... autonomy and attempts to keep HK's legislature under its firm grip," Wong wrote in a tweet.
He described the move as "the biggest-ever crackdown" on the city's anti-Beijing movement, saying authorities had disqualified "nearly all pro-democracy runners, from young progressive groups to traditional moderate parties".
The Civic Party, one of the city's most prominent anti-Beijing parties, confirmed four of its members had been disqualified: Alvin Yeung, Dennis Kwok, Kwok Ka-ki and Cheng Tat-hung.
“Today we are seeing the results of the relentless oppression that this regime is starting ... to take away the basic fundamental rights and freedom that are once enjoyed by all Hong Kong people under the Basic Law,” Hong Kong's mini-constitution, Kwok said in a news conference.
“They also try to drive fear and oppression into our hearts and this, we must not let them succeed,” he said.
How Hong Kong is run
Hong Kong is run by pro-Beijing appointees, but the city is due to hold elections in early September for the Legislative Council.
The 70-seat law-making body is deliberately weighted to return a pro-Beijing majority, with only half the seats elected by popular vote.
The rest are chosen by industry bodies and special interest groups who reliably vote for pro-Beijing figures.
But anti-Beijing parties had been hoping to capitalise on seething resentment towards Beijing's rule after huge anti-Beijing protests last year.
If they take all 35 electable seats they could hold a majority for the first time and block legislation.
During local council elections last year – the city's only full elections – anti-Beijing figures won 17 out of 18 districts.
However, election officials have been scrutinising the political views of candidates to decide whether they can run for the legislature.
Hong Kong says only those who promise to uphold the city's mini-constitution and pledge allegiance to both the local government and China can run.
In its statement, Hong Kong's government gave a list of political views and actions it said breached those commitments.
They included promoting independence, soliciting intervention by foreign governments and "expressing an objection in principle" to the new national security law Beijing imposed on the city last month.
Other nominees were still being reviewed, the government said in a statement expressing support for the disqualifications.
“We do not rule out the possibility that more nominations would be invalidated,” it said.
Hong Kong police arrest four under new law
Earlier on Thursday, Hong Kong activist Lee Cheuk-yan denounced the new national security law imposed by Beijing in response to last year's massive protests calling for greater freedoms. He criticised authorities for arresting four youths under the law on suspicion of inciting secession via online posts.
“Hong Kong politics keeps changing,” said Lee. “Now they are using the national security law against the young people … these young people are being charged just for the things they said.”
Late on Wednesday, Hong Kong police arrested four people aged 16-21 for suspected offences under the city's new national security law, the first such detentions outside of street protests since the legislation took effect a month ago.
In a press conference shortly before midnight on Wednesday, a police spokesman said the three men and a woman, all students, were suspected of being involved in an online group that pledged to use every means to fight for an independent Hong Kong.
"We arrested for ... subversions and for the organising and also the inciting (of) secession," said Li Kwai-wah, senior superintendent of a newly formed unit to enforce the security law.
"They wanted to unite all the independent groups in Hong Kong for the view to promote the independence of Hong Kong."
Police said some mobile phones, computers and documents were seized in the operation.
Controversial security law
The one-month-old law has chilled anti-Beijing protesting as activists along with academics and others wonder if their activities could be targeted.
The central government in Beijing imposed the national security law on the semi-autonomous Chinese territory after city leaders were unable to get one passed locally. The move has raised fears that Hong Kong's freedoms and local autonomy are being taken away.
Police did not identify the suspects or their group. An organisation called Studentlocalism, which announced it was disbanding just before the law took effect, said on Facebook that four former members had been arrested on secession charges, including ex-leader Tony Chung.
The police action appeared to target the Initiative Independence Party, which says on its Facebook page that it consists of former Studentlocalism members who have completed their studies and are overseas.
The party, which also posted the news of Wednesday's arrests, advocates for independence because it believes full democracy for Hong Kong is impossible under Chinese rule, its Facebook page says.
Li said only that the group in question had set up recently and that the posts were made after the law took effect late on June 30.
“They said they want to establish a Hong Kong republic and that they will unreservedly fight for it,” he said. “They also said they want to unite all pro-independence groups in Hong Kong for this purpose.”
He warned anyone who thinks they can carry out such crimes online to think twice.
Like Studentlocalism, many anti-government groups disbanded just before the law came into force, ranging from pro-independence Hong Kong National Front to anti-Beijing Demosisto, which was led by Wong.
Police have made a handful of other arrests under the new law, all of people taking part in protests and chanting slogans or waving flags deemed to violate the law.
China promised Hong Kong would have its own governing and legal systems under a “one country, two systems” principle until 2047, or 50 years after Britain handed back its former colony in 1997.
China, in justifying the new law, says issues such as separatism are a national security concern and, as such, fall under its purview.
Leading figure fired from academia
The latest arrests came one day after a leading figure in Hong Kong’s political opposition was fired from his university post.
Hong Kong University’s council voted 18-2 to oust Benny Tai from his position as an associate law professor, local media reported.
Tai has been out on bail since being sentenced to 16 months in prison in April 2019 as one of nine leaders put on trial for their part in 2014 protests known as the Umbrella Movement.
In a posting Wednesday on his Facebook account, Tai said he intended to continue writing and lecturing on legal issues and asked for public support.
“If we continue in our persistence, we will definitely see the revival of the rule of law in Hong Kong one day," Tai wrote.