1 July 2014
Last updated at 05:57
The rally comes days after 800,000 people voted in an unofficial referendum on universal suffrage
Crowds of people are expected to turn out in Hong Kong for what organisers say could be the largest pro-democracy protest in more than a decade.
Organisers said the annual rally, which marks the day Hong Kong was returned to China in 1997, will focus on pressuring Beijing for full electoral freedom.
It comes days after an unofficial referendum on how to choose the chief executive drew close to 800,000 votes.
The Hong Kong government said the 10-day poll had no legal standing.
Banners and billboards were put up around Hong Kong urging people to vote in last month’s poll
Organisers expect more than half a million people to join the rally, which will kick off in Hong Kong’s Victoria Park at 03:00 (07:00 GMT) and will head to the Central district.
Several campaign groups have also indicated that they will stage peaceful overnight vigils after the march.
“Public sentiment has dropped to the lowest point since 2003,” said rally organiser Johnson Yeung. “I believe more people will come out.”
The rally in 2003 drew half a million people, who demonstrated against proposed anti-subversion laws which were later scrapped.
Speaking at a ceremony to mark the 17th anniversary of the former British colony’s return to China, Hong Kong leader CY Leung said that the government was trying hard to forge a consensus on political reform.
“Only by maintaining Hong Kong’s stability can we sustain our economic prosperity. Only by sustaining Hong Kong’s prosperity can we improve people’s livelihood,” Mr Leung said.
Beijing has said it will hold elections for the role of chief executive in 2017, but the public will only have a choice of candidates selected by a nominating committee.
Campaigners want the public to be able to elect Hong Kong’s leader directly and believe that Beijing will use the committee to screen out candidates it disapproves of.
The unofficial referendum, organised by campaign group Occupy Central, allowed the public to decide which of three proposals – all of which involved allowing citizens to directly nominate candidates – to present to Beijing.
Hong Kong was handed back to China in 1997 following a 1984 agreement between China and Britain.
China agreed to govern Hong Kong under the principle of “one country, two systems”, where the city would enjoy “a high degree of autonomy, except in foreign and defence affairs” for 50 years.
As a result, Hong Kong has its own legal system, and rights including freedom of assembly and free speech are protected.