There are fears that a growing rift within the pan-democratic camp over how best to gauge public opinion may derail its push for meaningful reform ahead of the 2017 chief executive election.
The Occupy Central movement, with the backing of the Democratic Party, plans to hold a multimedia poll in June in which the public can vote on reform proposals.
The pan-democrat camp will then champion the most popular proposal to come out of the poll, to be conducted by the University of Hong Kong's public opinion programme.
But more radical factions want a return to 2010, when five geographical lawmakers resigned to trigger by-elections, which they hoped to use as a "de facto referendum" on the pace of democratisation.
They believe the resignations, resulting election campaign and by-elections would give the cause more publicity and offer a more accurate gauge of public opinion.
The radicals support the poll, and say the resignations would only be triggered if the government did not respond satisfactorily to its findings.
League of Social Democrats vice-chairman Avery Ng Man-yuen said: "A referendum triggered by resignations could bring a bigger political impact. We could use the election period to mobilise Hongkongers."
If the by-elections did not persuade the government, the next move would be to push the Occupy movement and block the main roads in Central.
"The two methods are not mutually exclusive; they're complementary," Ng said.
But moderate Occupy supporters argue that may confuse the public, while pan-democrats also have to weigh up the risk of losing seats in by-elections.
Five lawmakers - two from the Civic Party and three from the League - resigned in 2010 to trigger by-elections. They called on the government to implement universal suffrage and abolish all functional constituencies in the 2012 reforms.
But under a new law, a lawmaker who resigns mid-term cannot stand again for six months, ruling those who resign out of the by-elections.
Dr Kenneth Chan Ka-lok, then secretary-general of the Civic Party and deputy spokesman of the previous referendum campaign, said practical problems needed to be addressed if his allies decided to adopt the strategy again.
Because of the new rule, the democrats would need 10 people - five to resign and another five to run in the by-elections.
"The co-ordination would be more complicated than four years ago," he said. Pan-democrats would have to guard against competition among various factions to avoid losing a seat.
As it stands, the pan-democrats have just enough votes - a third of the 70-member Legco - to veto undesirable proposals.
"We will lose our veto power if some of our candidates are defeated in the by-elections," Chan said.
But Chan said he was still open to the idea as long as better links could be forged with the Occupy movement.
He warned that the by-election campaign would need a year of preparation.
The Reverend Chu Yiu-ming, an Occupy Central leader, said there were several practical issues to consider if by-elections were to be held.
"We do not dismiss a referendum but we have to draw a line to decide clearly how high a turn-out rate would make the referendum valid," he said.
Chu also said the risk of losing seats in Legco needed to be seriously considered.
A citywide de facto referendum could also be triggered by a district council constituency "super-seat" lawmaker, elected by 3.2 million voters who do not get a vote in any other functional constituency. But as the candidate must be a district councillor, it would be harder for pan-democrats to find a candidate well-known throughout the city.