(HONG KONG) — Hong Kong is a step closer to being left without a democratic opposition camp as authorities brought charges against 47 activists for conspiracy to commit subversion under the national security law.

It’s the most wide-reaching use yet of the controversial legislation which was imposed by Beijing eight months ago and would leave the majority of Hong Kong’s once-vocal opposition detained, in prison or in exile.

They are among 55 activists and politicians who were arrested in a sweeping police operation in January. Most of them were running in or organizing an unofficial primary in July last year to select candidates for September’s legislative election which the government later announced it would postpone by a year because of the pandemic.

The 47 detainees include some of Hong Kong’s most well-known activists, including veteran democrat Benny Tai, Claudia Mo and Leung Kwok-hung. Among the younger generation of activists, Lester Shum, Tiffany Yuen and Sam Cheung were also detained. Joshua Wong, who is already in prison, was also charged. John Clancey, the American lawyer previously arrested, was not among those who were charged on Sunday. The 79-year-old has been told to report to police again on May 4.

Under Hong Kong’s security law, they could all receive a maximum sentence of life in prison.

As the 47 appeared at West Kowloon Magistracy on Monday, prosecutors argued that the primary poll was part of a ploy to veto government budgets after gaining a majority in the legislature. Under Hong Kong’s Basic Law, its mini-Constitution, if a government budget is vetoed twice, then the Hong Kong leader must step down.

Outside of the court, hundreds of their supporters queued up for one of the limited seats inside the courthouse to listen to proceedings and some had been there to save a spot since 5 a.m.

By 9 a.m., the four rows of people queuing extended around the side of the court building and grew into a lively gathering — something not seen since COVID-19 restrictions and the security law were implemented.

The crowd chanted protest slogans and held up signs calling for the 47 defendants to be released.

Yellow umbrellas were raised and some people folded out copies of the pro-democracy Apple Daily as a symbol of resistance while others flashed the three-finger Hunger Games salute, used by protesters in Myanmar and Thailand.

One supporter, who did not want to divulge her name, told ABC News she was there to “stand up to Beijing’s bullying and fight for the remaining democracy in Hong Kong.” Like many of the other supporters outside of the court, the 25-year-old wore black, “to show unity”.

By the afternoon police had raised purple and blue flags several times, warning the crowd to leave the area as they were breaching the illegal assembly and national security laws, after some citizens chanted the banned slogan, “Liberate Hong Kong, revolution of our times.”

Speaking with ABC News, veteran activist Lee Cheuk-yan said the subversion charge is a clear attempt to “wipe out the pro-democracy camp for future elections.”

“The absurdity of the charge also shows again that the National Security Law is an instrument of political suppression against dissent and to spread fear among the people,” said Lee.

Authorities say the primary poll was an attempt to overthrow the government.

Before reporting to a local police station on Sunday, Sam Cheung told reporters that he hopes he’s still young when he comes out of prison and that he’d planned on studying for a PhD.

“I hope everyone won’t give up on Hong Kong. Everyone fight on,” said the 27-year-old.

Secretary of State Antony Blinken tweeted that the United States condemns “the detention of and charges filed against pan-democratic candidates in Hong Kong’s elections” and called for their immediate release. Blinken’s tweet went on to say, “Political participation and freedom of expression should not be crimes. The U.S. stands with the people of Hong Kong.”

Sunday’s events come just days before China’s annual parliament is set to meet later this week for the National People’s Congress. Beijing is expected to be announcing significant changes to Hong Kong’s electoral system, having said in recent weeks that only “Patriots” can run for office.

Beijing is also likely to tout the success of the security law as protests have died down since it came into effect.

Officials say the law is necessary to restore stability after mass protests gripped the semi-autonomous city for months in 2019, mounting one of the biggest challenges to China’s Communist Party rule in decades.

However, the legislation has come under intense criticism from the international community, with the U.S. and the European Union saying the law stifles freedoms meant to be guaranteed under the “one country, two systems” arrangement.

Prominent activists already in custody include media tycoon Jimmy Lai and 25-year-old Agnes Chow, while many others have fled the city.

Copyright © 2021, ABC Audio. All rights reserved.