With his rapid but articulate delivery, Tam Tak-chi is better known not as a radical activist but as radio DJ "Fast Beat" - one half of a popular combination with "Slow Beat" Raymond Chan Chi-chuen.
But while "Slow Beat" was elected as a People Power lawmaker in 2012, Tam remained better known for his more than a decade of work in television and radio - including some unimpressive forays into soap-opera acting - than for his political views.
That all changed last month, when Tam surprised his fans by wading into the heart of a political battle that has left the pan-democratic camp in disarray.
Tam led a group of People Power members - under the banner of "Supporters of Occupy Central" - to disrupt an "oath-taking" event by the Democratic Party in support of the planned civil disobedience movement.
The chaotic scenes were an embarrassment for the Democrats, a party opponents say has wavered in its demands for democracy since party members held a closed-door meeting with Beijing officials at the central government's liaison office four years ago. That was against the advice of allies who had rejected proposals put forward by the government for the last chief execution election in 2012.
But those allies have this time come to the defence of the party, saying Tam's demonstration in no way helped to unite the city's pan-democrats in their pursuit of universal suffrage for 2017.
"Unite?" Tam asked in response. "Say there's a man who always beats his wife violently. Only by way of a divorce could the woman get a new life," he said of his group's attitude to its erstwhile allies. The Democratic Party is more closely aligned with other moderate groups such as the Civic Party, Labour Party and the Professional Commons.
Tam dismisses such an alliance, saying: "It's only because they are ignorant."
The 41-year-old's outspoken style has previously landed him in hot water, once costing his former partner Chan a job at Asia Television. Four years after making a name for themselves as transport presenters at Commercial Radio, Tam and Chan attracted hordes of viewers when they hosted a game show for the free-to-air station in the late 1990s.
But Tam soon voiced his displeasure with the station in a newspaper column, citing "crap production" in the studio.
Tam's contract wasn't renewed, and Chan decided to leave the station.
"I don't blame him," said Chan. "I came and went together with him. It would have been meaningless if only one were left behind."
The two left in 1999 and moved on to Metro Radio. Tam later became its creative director, before the pair, again, left together in 2007.
Tam was later invited to work at ATV for a second time, only to walk away after making another public complaint, this time over the treatment of contestants in the Miss Asia pageant and the actions of ATV's controversial mainland investor, Wong Ching.
Tam also reported being attacked by three men earlier this year. His attackers are said to have told him: "Don't use foul language."
Chan has said his social activism is down to Tam's influence.
"I've learned from him how to challenge authority. I might have just been an obedient guy had I not known him," said Chan, who made headlines after the poll as the city's first openly gay lawmaker.
When Chan ran for Legco, Tam posted stickers bearing his candidate number onto billboards promoting other candidates, which almost landed him with a criminal record.
In an interview in 2011, Tam said he would never join a political party, citing Karl Marx's theories on their impotence. But he has since joined People Power and serves on its executive committee. Most of the "Supporters of Occupy Central" activists are party members.
Since the group disrupted the Democratic Party event last month, Benny Tai Yiu-ting, the University of Hong Kong associate law professor co-organising Occupy Central, has distanced himself from Tam's group, saying campaigners for the civil disobedience movement would form their own network of supporters.
Tam said he supported Tai's movement, but was worried about the Democratic Party - his main target - "hijacking" it.
He stresses the importance of public nomination of candidates in the chief executive election, something the Democratic Party has shied away from.
But his criticism has also taken a personal tone at times.
Tam, who holds a master's degree in theology, called Reverend Chu Yiu-ming, one of the co-organisers of Occupy Central, "Christ's con" at last month's event, after Chu officiated the oath taken by Democrats, which Tam called "fake". Chinese University sociologist Professor Chan Kin-man, meanwhile, is "highly dubious", according to Tam, as he was one of the Democrats who met liaison office representatives four years ago.
Tai expressed disappointment at this kind of protest, saying he was heartbroken to hear Chu called such names.
But Tam insists such tactics are needed to prevent Occupy Central, which plans to rouse 10,000 activist to block streets for universal suffrage, being manipulated by the ill-intentioned.
He says he can vouch for the identity of 1,200 of the 2,000 supporters who have signed up for his group, including radical lawmaker "Long Hair" Leung Kwok-hung and former lawmaker Albert Cheng King-hon.
"We don't want Occupy Central to be hijacked by people in the Democratic Party," Tam said.
"Nor do we just want to hurl criticism - as people such as Raymond Wong Yuk-man do," he said, referring to the lawmaker who split from People Power.
"We want to show our conditional support. We will support proposals as long as they incorporate public nomination and are in line with the International Covenant on Civil and Political Rights."
1994: Graduates with Bachelor of Arts, University of Hong Kong
1994-99: Commercial Radio presenter
1997-98: ATV, part-time host
1999-2006: Metro Radio presenter
2009: Starts career as host on several online radio stations
2013: Joins People Power