Kelly Osbourne has declared she will not set foot in Russia until jailed punk stars Pussy Riot are released from prison.

Two members of the Russian girl group, Nadezhda Tolokonnikova and Maria Alekhina, are currently serving two-year prison sentences for performing a protest song against President Vladimir Putin at a Moscow church.

Madonna and Sir Paul MCCartney are among the famous faces who have spoken out in support of the jailed musicians, and now Kelly Osbourne has thrown her weight behind a campaign to free the women.

She has even vowed not to visit Russia until the pair is released from prison.

In a post on her Twitter.com page, she writes, "I support the Vagina Riots (Pussy Riot) and will never go back to Russia until they are released!... Pussy Riots (sic) for life!"

The two jailed rockers are currently appealing against their convictions.