The case was the largest prosecuted under the city's 2020 national security law, imposed by Beijing after massive, sometimes violent pro-democracy protests the previous year.

The group -- made up of some of the city's best-known political opposition figures -- was arrested in early 2021, and many have been detained ever since.

"Hong Kong has fallen for three years and eight months, how can I feel?" said businessman Jerome Lau, who was among people queuing for public seating in the morning.

"Not even just three years and eight months, this has been going on from 2019 till now."

At dawn, more than 200 people were in line, umbrellas held up against the cold morning drizzle and surrounded by a heavy police presence.

"There are many sad moments for me, and I feel people are risking their lives for democracy here," said Sophie Gan, 34, a healthcare worker who lives in Germany.

"It's quite difficult" to have hope about Hong Kong's democratic future, she said.

The vice-chair of Hong Kong's last standing opposition party was outside court on Tuesday too.

Dickson Chau said that jailing the campaigners en masse would be "depressing" and would give "a clear political signal" that dissent from Beijing incurs a heavy price.

"I wonder if this would prompt more people to emigrate, or those who left wouldn't dare to come back to visit friends," he said.

Law student Jack said he believed already "people's passion for political participation has dissipated" in Hong Kong's increasingly restrictive environment.

- 'Restore faith through action' -

The 45 defendants were charged after they held an informal primary election in 2020 to better their chances of winning a pro-democracy legislative majority.

On Tuesday, only five spectators were allowed in the courtroom's public gallery as most spots were taken up by defendants, their family members and lawyers.

Judge Andrew Chan repeatedly asked for quiet as people in the courtroom reacted to the jail terms, ranging from four years and two months to 10 years.

"Today's sentencing is already suppression. No matter if the sentence is four years or ten years, it should not stand," activist Figo Chan told journalists afterwards.

Outside, the mother of one defendant silently held up a placard reading: "The righteous shall live, the wicked shall perish."

She was taken away in a police van within seconds, according to video footage from Hong Kong media.

Many defendants remained defiant too, releasing statements to coincide with the sentencing as they could not speak in court.

Former Hong Kong journalist Gwyneth Ho's statement included an impassioned plea to Hong Kongers: "Restore faith in democratic values through action".

Ho also called it "comical" for authorities to cast their informal poll as subversion.

"Following such logic, one may as well claim that democracies around the world suffer subversion attempts every 4 to 6 years," she wrote.

"In a 1984-esque reality, though, democratization -- or just calling for it -- amounts to subversion of state power."

Hong Kong authorities have defended their use of the security law as being necessary to restore order following the 2019 protests.

One of the convicted defendants, who requested anonymity to protect their family, earlier told AFP that the case was a "test of Hong Kong's rule of law and the city's future".

"I don't think this is the ending... As long as you're still alive, there is hope. The key is whether the spirit can be passed on."