A Hong Kong court has struck down the government's request to ban from the internet the unofficial anthem of the island's pro-democracy movement.

Judge Anthony Chan ruled that granting the ban could have had "chilling effects" on freedom of speech.

Authorities have been angered by hearing Glory to Hong Kong played instead of the Chinese national anthem during international sports events.

They have taken a tougher stance towards protests in recent years.

Hong Kong is part of China, but has had some autonomy since the end of British rule in 1997. Campaigners say that democratic freedoms have been gradually eroded since then.

They say attempts to ban the song are another sign of Beijing's crackdown on dissent against the Chinese government.

Authorities have tried to erase or mask all traces of the song online for months. Glory to Hong Kong has also been banned in schools since 2020.

The Hong Kong government has also petitioned Google to have the song removed or ranked lower in search results; a request that the company has consistently denied.

Justice Minister Paul Lam Ting-kwok requested in June that the court grant an interim injunction to ban the song from being promoted, disseminated, or performed "with the intention of inciting others to commit secession or with a seditious intent".

But in his ruling, the judge wrote: "I believe that the intrusion to freedom of expression here, especially to innocent third parties, is what is referred to in public law as chilling effects". He did not elaborate on who he meant by "innocent third parties".

The protest tune was written in Cantonese during major demonstrations in 2019, and was adopted widely by the protesters. It includes the lyrics: "Revolution of our times. May people reign, proud and free, now and evermore. Glory be to thee Hong Kong".

In response to the demonstrations, China imposed a sweeping national security law to restore stability to the city. Critics said it was designed to suppress dissent and reduce Hong Kong's autonomy.

Last year, a harmonica player was arrested for playing the song outside the British consulate in Hong Kong to mourn the death of Queen Elizabeth II.