Europe should immediately signal its joint will to strengthen the eurozone, IMF chief Christine Lagarde said Saturday on the eve of Greek elections which are crucial for the future of the monetary union. "In the very short term, perhaps in less than three months, it is necessary for Europeans, particularly those in the heart of the eurozone, to give strong signals about their collective will to buttress their monetary union," she told France's Liberation newspaper. Lagarde, a former French finance minister, stressed the need for common authority steering the bloc and not "national central banks", stricter supervision of the financial sector and mechanisms to resolve banking crises. She also called for the creation of a eurozone treasury, adding: "All the countries of the eurozone must accept a budgetary, banking and financial community in which decisions will be taken in a collective manner." Greece, which along with Portugal and Ireland has received an international credit lifeline, returns to the polls Sunday for its second election in six weeks. The vote will be watched closely around the world as all the top candidates are now calling for renegotiation of Greece's bailout deal despite warnings that the country must toe the line or leave the euro. European leaders, in particular German Chancellor Angela Merkel, have said the terms must stand but officials say privately there is some wiggle room and a willingness to meet Greece's need to restart economic growth after five years of recession. Greece is currently on its second international bailout loan of 130 billion euros ($164 billion) and conducted a 107-billion-euro private debt write-off earlier this year. Less than a week back, the eurozone agreed on a banking rescue of up to 100 billion euros ($125 billion) for Spanish banks. And Italy, struggling to allay fears over its debt, adopted a series of growth-boosting measures along with plans to sell off state assets and trim the number of government workers.