The government issued a statement saying that the nomination of a candidate, whom it did not identify, had been ruled invalid. Wong became known as the young face of Hong Kong's 2014 "Umbrella Movement" protest movement. He has been less prominent in the current protest movement, which has been leaderless and whose participants have sought to remain anonymous.
Hong Kong's leader says the city is at risk of falling into a recession as it enters its fifth month of pro-democracy protests, and she says her priority was ending violence first before a political resolution.
Chief Executive Carrie Lam said Tuesday that if third quarter data due for release on later this week shows negative growth, then the semiautonomous Chinese city's economy will have entered a technical recession.
Hong Kong has been gripped for more than four months of protests, with demonstrators and police frequently in violent street clashes. The unrest has hit the city's tourism and retail industries.
Lam told reporters before weekly Cabinet meeting that finding political solutions to the problem would take a backseat to authorities' efforts to quell the violence.