An attempt to put a definitive figure on the number of protesters in the July 1 rally has been proposed by two statistics experts - but they have accused march organisers of snubbing them.
There has always been a massive gap between the organiser's turnout figures and those given by professors Paul Yip Siu-fai and Robert Chung Ting-yiu from the University of Hong Kong, who have been accused of deflating the number in favour of government interests. This year their figures were just a quarter of those given by the organiser, the Civil Human Rights Front.
Yip, who specialises in demographics, and Chung, director of the university's public opinion programme, claimed to champion democracy and said it was important to be scientifically correct.
"It would be a big day for Hong Kong if all parties could reach an agreement on how to count the number and if all these estimates are within reasonable range," said Yip, who has given turnout figures for the march every year since 2003.
His estimates put the turnout this year at between 70,000 and 90,000 people; Chung had between 98,000 and 112,000; the Civil Human Rights Front, a coalition of more than 40 civic and political groups, put the number of protesters at 400,000.
"We have tried to ask [the Front] to count it together with us, to watch the video footage together, but nobody was interested," Yip said. "I opened the door, invited them to come over and review the clips and the counting process together, but they snubbed me.
"Some people try to say I am politically motivated, but I'm not. I'm not for Leung [Chun-ying]; I'm not for [Henry] Tang [Ying-yen]."
Chung said: "We really hope, with an agreed methodology, an independent person or independent media organisation could do this, so that we could pack up. But it doesn't seem likely.
"It doesn't matter who does it. What's important is that the methodology is fair."
He said getting it right was a quest for truth.
"If there is an objective figure, even if it's within a range, it's better than making a guess based on your feelings," he said. "Many protest organisers, in the past and now, have indeed only made guesses. It's unscientific to colour these numbers with political motives. Our job is to be blind to ideological issues and beliefs, and be true to what we do.
"Chinese societies have advanced through the advancement of science and democracy, though they sometimes go against each other here. If you ask me which is the more important, then to me, a scholar, of course it's science."
Eric Lai Yan-ho, convenor of the Civil Human Rights Front, said he did not know of any instance where their group had refused to work with the academics, and said any ideas on how to improve the count should be considered.
Political commentator Albert Cheng King-hon criticised the scholars' estimates as "illogical", drawing comparisons between how crowded Causeway Bay was on July 1 and June 4.
"On June 4, 180,000 turned up and the areas around the park weren't that seriously congested. But on July 1, the streets and areas around Victoria Park were solidly packed with people. Some people had to wait for several hours before they could join the crowd inside the park," he said.