A protester shouts at police guarding outside the Greek parliament in Athens June 15, 2011. Greek police fired tear gas at demonstrators as tens of thousands of grassroot activists and unionists vowed to converge on Athens' central Syntagma (Constitution) Square on Wednesday as Prime Minister George Papandreou prepared to push through a new five-year campaign of tax hikes, spending cuts and selloffs of state property to continue receiving aid from the European Union and International Monetary Fund and avoid default. REUTERS/Yannis Behrakis (GREECE - Tags: POLITICS BUSINESS CIVIL UNREST EMPLOYMENT)