The vote, held 10 days after China imposed a sweeping new security law on the city, was designed to narrow down the number of pro-democracy candidates in September elections to the city's legislature.
The opposition camp is hoping to seize a historic majority in the parliament, through careful coordination to avoid splitting the pro-democracy vote, and in making headway in the functional constituencies, seats chosen by business and professional groups which form half of the legislature.
This would be a hard task at the best of times, and the government has already hinted that it may bar potentially dozens of candidates from those elections under the new security law, which criminalizes secession, subversion, terrorism, and collusion with foreign forces.
Mood among the opposition was considerably boosted Monday, however, after organizers said some 600,000 votes were cast in the primary election. That's around 27% of the number of people who voted in the most recent legislative elections, and far above organizers' original target of 170,000.
"Hong Kong people have made history again," Benny Tai, one of the organizers, said after the polling ended on Sunday night. "Hong Kong people have demonstrated to the world, and also to the authorities, that we have not given up to strive for democracy."
Erick Tsang, Hong Kong's Secretary for Constitutional and Mainland Affairs, said on Friday that the primaries might violate Hong Kong's new national security law because of the candidates' political stance, according to Hong Kong public broadcaster RTHK.
"Those who have organized, planned or participated in the primary election should avoid carelessly violating the law," he said.
Late Friday night, police raided the offices of the Public Opinion Research Institute, a polling company that was helping to organize the primary. Organizers denounced the move as an attempt to disrupt the vote or intimidate people, while police said it was related to a tip about potential hacked data.
The police raid may have assisted in helping to publicize the primary election, however, with the news of the event circulated throughout the city.
Speaking to the South China Morning Post, one woman, who moved from China to the city 20 years ago, said she took part in the vote because she feared "Hong Kong will become just like the mainland one day."
"I did wonder whether it would be the last time I took part in such a primary," Kitty Yau told the paper. "But I am not afraid of any 'white terror' as I am just exercising my rights."
Security law
There has been a marked chill on the city's politics since the passage of the security law, which was imposed directly by Beijing, bypassing Hong Kong's legislature.
In the hours after it became law, multiple political parties disbanded, including one founded by prominent activist Joshua Wong. Online, people scrubbed social media profiles and deleted accounts, and asked contacts to wipe WhatsApp messages from them. Shops and restaura
