A group of leading musicians has called on Russia's president Vladimir Putin to give a fair hearing to members of a punk band facing prison for performing a "legitimate protest".
The trio, Pussy Riot, face up to seven years behind bars after staging a performance in a Moscow cathedral calling on the Virgin Mary to remove President Putin from power.
In a letter to the Times newspaper, the group of musicians - including Jarvis Cocker, Pete Townshend, Martha Wainwright and Neil Tennant - said that the incident by the band amounted to "a minor breach of the peace".
Requesting the release of the three band members, Nadezhda Tolokonnikova, 22, Yekaterina Samutsevich, 29, and Maria Alekhina, 24, it states: "We are extremely concerned about the treatment they have received since their arrest and during their trial."
The letter continues: "Dissent is a right in any democracy and it is entirely disproportionate that they face seven years in jail for what we consider a preposterous charge of 'hooliganism motivated by religious hatred'.
"We are especially concerned about recent reports that food is being withheld from them and that they have appeared in court in a cage.
"We believe firmly that it is the role of the artist to make legitimate political protest and fight for freedom of speech.
"As he visits the United Kingdom this week, we ask President Putin to ensure these three women receive a fair hearing."
The Russian premier is due to meet David Cameron for talks later.