Tens of thousands of Hong Kongers have lined up to vote, joining hundreds of thousands of others who cast electronic ballots in the first three days of an unofficial referendum on democratic reform.

Tensions have soared in Hong Kong over how much say residents of the former British colony can have in choosing their next leader, who is currently hand-picked by a 1,200-member committee of mostly pro-China elites.

If many people come out to voice their opinion, but the Beijing central government ignores that voice, then it is over for Hong Kong

Chan Chi-chung, Hong Kong voters

Beijing, which has pledged to allow Hong Kongers to choose their own leader starting in 2017, has balked at letting members of the public nominate their own candidates, saying they would have to be vetted by a Beijing friendly committee.

Pro-democratic organisers of the Occupy Central with Love and Peace movement are offering voters three proposals on so-called public nomination.

They have vowed to hold a mass protest if the former British colony's government, which has carried out a consultation on electoral reform, does not come up with a proposal that meets their standards.

The plan involves rallying at least 10,000 people to shut down the city's central business district and has alarmed businesses in the Asian financial hub.

By 10pm Sunday, nearly 700,000 ballots had been cast since voting started Friday, including about 440,000 through a smartphone application. About 200,000 more were cast online despite a massive cyberattack that left the site intermittently inaccessible and forced organizers to extend voting by a week until June 29.

'Political farce'

And about 48,000 people cast ballots at 15 polling stations, which organizers were operating on two successive Sundays.

The outlook for Hong Kong's democratic development "Is quite pessimistic but we are also proactive and we will try our best to make miracles happen," said Chan Chi-chung, a teacher voting at Hong Kong Polytechnic University.

"If many people come out to voice their opinion, but the Beijing central government ignores that voice, then it is over for Hong Kong."

Voters at one polling station were met by a small-group of protesters decrying the vote as a crime. 

The central government's liaison office has called the vote "a political farce that overtly challenges the Basic Law," referring to the mini-constitution that promises a high degree of autonomy under the principle of "one country, two systems" for Hong Kong after it became a specially administered Chinese region in 1997.

Hong Kong's current leader, Chief Executive Leung Chun-ying, has also said the three options don't comply with the law. Justice Secretary Rimsky Yuen said there was "simply no legal basis" for the vote, which should be seen merely as "an expression of opinion by the general public."

Source: Agencies