Meanwhile, Hungary has been accused of favouring Blue Stream because of its close ties with Moscow. Speaking at a news conference in Budapest, the International Energy Agency Chief, Claude Mandil, urged Hungary not to rely only on the extension of Gazprom's Blue Stream pipeline to diversify its supply - saying it is just a new route, not a new source.

Mr Mandil suggested Hungary - which gets 80% of its gas from Russia - should consider three projects - Blue Stream, the EU's Nabucco, which will bring gas from the Caspian, and an LNG terminal on the Adriatic.