Britain found itself embroiled in a similar scandal when WikiLeaks founder Julian Assange was granted asylum last year at London’s Ecuadorian Embassy, where he remains.
He is facing extradition to Sweden on accusations of sex crimes and has expressed fears that if he goes there he could also face extradition to the US.
Earlier this week, Snowden’s girlfriend blogged about the couple’s life in Hawaii and her uncertainty about the future without her “man of mystery”. Lindsay Mills, 28, wrote: “I don’t know what will happen from here.”