Alexis Tsipras, leader of the Radical Left Coalition SYRIZA, casts his vote in Kypseli area, central Athens, Greece, June 17, 2012. Greek political leaders cast their ballots on Sunday in crucial general elections and expressed optimism over the results of the polls that could determine Greece's economic future and membership in the European single currency zone.

Alexis Tsipras, leader of the Radical Left Coalition SYRIZA, casts his vote in Kypseli area, central Athens, Greece, June 17, 2012. Greek political leaders cast their ballots on Sunday in crucial general elections and expressed optimism over the results of the polls that could determine Greece's economic future and membership in the European single currency zone. [Xinhua]