Gay actor and comedian Stephen Fry has taken to Twitter to vent his anger over an anti-gay bylaw in St Petersburg.
The bill, submitted in November by the United Russia party to ban "promotion" of gay lifestyles, is discriminatory, Russian activists said.
Fry tweeted: "Hell's teeth, something must be done to stop these fantastical monsters. Will talking about Tchaikovsky be banned?"
"Promoting" homosexuality may lead to fines of between £106 and £10,600 under the new law.
The law defines its target as "public activities aimed at the propaganda of sodomy, lesbianism, bisexuality, and transgender among youth".
It outlaws "spreading information that can damage the health and moral development of underage children, and make them believe that both traditional and gay relationships are normal".
A protest aginst the law was quickly broken up by police. One person was arrested.
Activists have been campaigning for years for the right to hold a gay pride parade in St Petersburg but have been forbidden. The former mayor, Yury Luzhkov, described activists as "satanic".
In 2011 the European Court of Human Rights forced Russia to pay €30,000 (£25,000) in compensation to gay rights activists.