HONG KONG — The Hong Kong authorities on Tuesday barred Joshua Wong, a prominent democracy activist, from running in district council elections next month, a blow to the protest movement’s efforts to convert deep anger toward the authorities into electoral gains.

The government cited Mr. Wong’s earlier assertions that the future of Hong Kong should be determined by its people. An official said those statements were incompatible with the Basic Law, Hong Kong’s mini-constitution, which states that the semiautonomous city is part of China.

“The candidate cannot possibly comply with the requirements of the relevant electoral laws, since advocating or promoting ‘self-determination’ is contrary to the content of the declaration that the law requires a candidate to make to uphold the Basic Law and pledge allegiance” to Hong Kong, the government said in a statement.

Mr. Wong said the decision showed that China’s central government was manipulating the election, which is expected to be a key test of public sentiment about the protest movement.

“I strongly condemn the government for its political screening and censorship, and for depriving me of my right to stand for election,” Mr. Wong said in a statement. He added that the official who made the decision had been relegated to a role as the “thought police.”

The district council election, which will be held on Nov. 24, is usually fought over local issues, like bus stops and neighborhood beautification. But the race is taking a broader political significance this year. Whichever side wins the most seats will control 117 votes in the 1,200-member election committee that chooses the next chief executive, Hong Kong’s top government position.

The pro-democracy camp’s fears of even wider prohibitions on their candidates seeking office have not been realized, as Mr. Wong will most likely be the only candidate barred from the district council race.

Ezra Cheung, Tiffany May and Elaine Yu contributed reporting.