Over a hundred people gathered outside the British Consulate General in Admiralty on Wednesday night - urging the UK government to act in support of the democracy protest movement.
They called on the UK to terminate the Sino-British Joint Declaration, saying this would mean Beijing no longer had sovereignty over the city.
They said Britain has a responsibility to do something for the SAR under the treaty - especially with people's demands falling on deaf ears.
They also want Hong Kong to rejoin the Commonwealth.
The rally organiser said they handed a petition to a representative of the consulate - just hours ahead of the general election in UK.