The Greek prime minister has called a surprise early election.In a televised address to the nation, Costas Karamanlis said the country needed to clear the political landscape in order to take measures to deal with its economic downturn. Karamanlis’s four-year term would normally end in 2011. He is expected to seek parliament’s dissolution tomorrow. A government source was quoted as saying the poll would be on October 4, but that has not been confirmed. . Greece is struggling to cope with the global financial crisis that is threatening to push its economy into recession this year while high unemployment and its national debt, the euro zone’s second biggest, is ballooning. The scandal-plagued conservative New Democracy government trails the main opposition socialist PASOK party, led Georgios Papandreou, by about 6 points in opinion polls.