Greece's highest court to rule on legality of referendum

Council of state to question whether referendum violates constitution as yes and no camps appear neck and neck in polls

Greece's highest administrative court will rule on whether the country's bailout referendum violates the constitution, amid growing concern that the hastily organised vote falls short of democratic standards.

With less than 48 hours until polling day on Sunday, the yes and no sides will stage large rallies in Athens on Friday evening. The prime minister, Alexis Tsipras, is expected to turn out at the no rally, having attacked his eurozone partners for trying to "blackmail" his country into accepting a bad deal.