More than 500,000 people have voted in Occupy Central’s online poll on options for the 2017 chief executive election since it launched at noon on Friday, despite the online voting system coming under one of the largest cyberattacks in history according to experts.
By 3pm on Saturday afternoon, 500,436 people cast their votes in Occupy Central’s unofficial “referendum”.
That was more than double the figure in the two-day mock election organised by the University of Hong Kong on March 2012, where 223,000 voters cast their ballot to have their say on who the city's new chief executive, while the actual election was decided by a 1,193-strong committee.
The turnout so far is also 80,000 people away from organiser Benny Tai Yiu-ting’s target to get 580,000 people to vote, to match the turnout of a Legislative Council by-election in May 2010, which was triggered by the resignation of five geographical lawmakers who hoped to use the poll as a "de facto referendum" on the pace of democratisation.
Watch: Hongkongers voice their opinion on the referendum, democracy, and Occupy Central
Hong Kong permanent residents can pick one out of three shortlisted proposals on how to elect the next chief executive in 2017 via the smartphone app “PopVote” or by visiting the website popvote.hk until June 29.
They can also express their preference for whether Legco should veto any reform plan that does not provide a genuine choice of candidates to the public in 2017.
The voting platform has been operating smoothly despite being inundated by a massive distributed denial of service (DDoS) attack of more than 300 gigabits per second at its peak, prompting organisers to extend the voting period from three days to ten.
Professor Benny Tai Yiu-ting, one of the founders of the pro-democracy Occupy Central movement, described the attack as a "world-class intrusion".
"The world record attack is only 400 gigabits per second," he said.
Matthew Prince, the chief executive of CloudFlare, the website maintenance company that is providing technical support to the popvote.hk site, described the extent of the cyberattacks on Twitter  and said the company was well prepared to counter the attacks.
People unable to vote online will be able to visit one of the 15 actual polling stations set up throughout the city on June 22, with another 10 stations open on June 29. A further opportunity to vote would be available to those wanting to vote at night at a polling station in City University from June 23 to June 28.
The central government's liaison office in Hong Kong has dismissed the vote as a "farce". A government spokesman said the “so-called civil referendum" had no legal effect as it did not exist in the Basic Law or local laws.
"The HKSAR Government has repeatedly stated that proposals on political development should be, legally, strictly in accordance with the Basic Law and relevant Interpretation and Decisions of the Standing Committee of the National People’s Congress,” the spokesman said.
On public nomination, an element included in all the three proposals, the spokesman said the power to nominate chief executive candidates is vested in the nominating committee only under the Basic Law.
He also said this element was highly controversial in legal, political and operational aspects so the government believed it was unlikely to be adopted.
“There are many opinions in the community, including those from legal professional groups and individuals, that ’civic nomination’ will bypass or undermine the substantive powers of the [nominating committee] to nominate candidates and hence is, legally, highly controversial.”
“Politically, such a proposal will unlikely be conducive to forging consensus, and operationally, the feasibility of implementation is questionable,” he said.
But Occupy Central co-organiser Dr Chan Kin-man said the government was avoiding public voices by hiding behind "ridiculous excuses".
"We have never said that our referendum has any legal binding effect," Chan said. "Why doesn't the government hold its own poll if it says ours has no credibility?"
Additional reporting by Lai Ying-kit