Organisers expect 200 activists from about 13 local groups to join a march today in support of whistle-blower Edward Snowden, who is in hiding in Hong Kong.
The protest, starting at 3pm at Chater Garden in Central, will see the activists march to the US consulate in Garden Road before continuing to the government headquarters in Admiralty, where the 2-1/2-hour demonstration is expected to conclude.
Pan-democratic lawmakers Albert Ho Chun-yan, Charles Mok, and Claudia Mo Man-ching are among those who have agreed to address the protest as a show of solidarity against Snowden's extradition to the US.
Pressure groups have joined forces with a "Support Snowden" campaign after he revealed in Hong Kong that he was behind a series of leaks exposing the US government's collecting of private internet and telephone data, as well as extensive hacking by Washington.
In an exclusive interview with the South China Morning Post this week, Snowden said he was prepared to put his fate in the hands of the city's people and its legal system.
The groups taking part include the Civil Human Rights Front, which organises the annual July 1 pro-democracy march; socialist groups Socialist Action and Left 21; and the gay group Nu Tong Xue She.
A spokesman for organiser In-media, Damon Wong Chun-pong, yesterday said: "We condemn the Obama administration for violating our rights and privacy, and we call on Washington not to prosecute Mr Snowden."
Wong also called on the Hong Kong government to protect the whistle-blower.
The US consulate yesterday issued a warning to Americans to stay away from demonstration areas, and not to go to the consulate unnecessarily.
Mok, who represents the IT sector in the legislature, said: "I think the US consulate have over-reacted a bit."
Wong stressed that the protest would be peaceful. "We plan to hand in our petition letter to the US government, and that is all," he said.