Alla Perfilova, better known by her stage name Valeriya, on the three Russian pop stars black-listed in Latvia, performs during a concert in Russia's second city of Saint Petersburg, on Dec. 19, 2013.
Photo by AFP
Protesters are calling on Downing Street to bar two high-profile Russian pop stars who are vocal supporters of Vladimir Putin from entering the UK for a gala performance next weekat the Royal Albert Hall.