Among the Hong Kong activists facing jail on Thursday is an octogenarian barrister dubbed the "Father of Democracy" who Beijing once asked to help draft the city's mini-constitution and was often dismissed by younger activists for being too moderate.

In the broad spectrum of Hong Kong's democracy advocates, 82-year-old Martin Lee would not be considered a firebrand.

For decades he has campaigned in vain to see democracy in Hong Kong but always advocated working alongside authorities in Beijing, even as they branded him a traitor.

He was critical of younger generations that favoured a more confrontational approach and remained a vocal opponent of political violence. 

Now he faces up to five years in jail for helping to organise a huge, but peaceful, rally during the months of political unrest that convulsed Hong Kong in 2019.

"Finally I've become a defendant," he quipped after his arrest last year. 

"How do I feel? I'm very much relieved. For so many years, so many months, so many good youngsters were arrested and charged, while I was not arrested. I feel sorry about it."

That a figure like Lee could be going to jail illustrates how the space for dissent has been all but squeezed out of Hong Kong, even for more moderate voices.

Son of a general 

Lee's career mirrors Hong Kong's recent history and political pragmatism runs in his family. 

His father Lee Yin-wo was a general in the Kuomintang forces that lost the Chinese civil war to Mao Zedong's Communists.

Despite their differences, the general-turned-teacher remained in touch with top Communist party leaders, including Zhou Enlai.

The younger Lee was a typical product of Hong Kong's local elite under colonial rule. 

He studied law in Britain and flitted comfortably between English, Cantonese and Mandarin. When Hong Kong was convulsed by leftist riots in 1967 during the Cultural Revolution, Lee went to defend people charged with spearheading the unrest.

In the run-up to Hong Kong's 1997 handover to China he was one of the lawyers picked by Beijing to draft the Basic Law.

That document grants Hong Kong certain freedoms and autonomy unseen on the authoritarian mainland under a model dubbed "one country, two systems", including the eventual promise of universal suffrage.

Critics say Beijing's has demolished that promise in recent years and Lee was among the first to sound the alarm over China's assurances that Hong Kongers could keep their way of life. 

After Beijing sent tanks to crush the Tiananmen Square student protests in 1989, Lee started criticising Beijing. 

He was turfed out of the Basic Law committee and soon branded a traitor by state media.

Things will explode

He went on to found the city's first pro-democracy party and joined the post handover Beijing opposition after handover.

But he always maintained support for "one country, two systems" and the idea that Hong Kong was part of China.

After the handover, Britain's Prince Charles wrote in a diary entry: "Thus we left Hong Kong to her fate and the hope that Martin Lee, the leader of the Democrats, would not be arrested."

As opposition to Beijing's rule among many Hong Kongers hardened, Lee was often criticised by those who felt his generation's tactics had failed to achieve anything close to suffrage.

Student-led democracy protest erupted in 2014 and a new generation of firebrand activsts like Nathan Law and Joshua Wong came to the fore -- a precursor to the even larger and sometimes violent rallies of 2019.

Lee was aware that his calls for a more patient approach had become less popular. 

"I'm a public enemy from China's point of view. And the kids don't like me, either, because I am not agreeing with their objects," he told the New York Times last year.

But he said he recognised why so many younger Hong Kongers were frustrated and accused Beijing of failing to live up to its own commitments.

"Now China doesn't even want to follow the rules of its own book," he told The Guardian last year as the city was blanketed by a sweeping new national security law. 

"But if you continue to suppress people like this, things will explode."

He remained defiant. 

"Even if you jail me, kill me, I will still point out it's their fault. Democracy will come to China one day."