Hong Kong's democratic opposition failed to win back a crucial legislative council seat in an election on Sunday that would have restored some of its veto power at a time when the China-ruled city's freedoms are under strain.

The democratic camp's main candidate, Lee Cheuk-yan, lost to Rebecca Chan Hoi-yan of the pro-Beijing Democratic Alliance for the Betterment and Progress of Hong Kong (DAB), by around 13,000 votes, or about 6 percent of the total.

Another democrat, Frederick Fung, who ran as an independent after a row with the opposition camp, split the vote to the benefit of the DAB.