Factbox - Mechanics of the Greek referendum on Sunday

Greek Finance Minister Yanis Varoufakis removes his helmet as he arrives on his motorbike prior to a meeting at the office of Prime Minister Alexis Tsipras in Maximos Mansion in Athens, Greece, July 1, 2015. REUTERS/Jean-Paul Pelissier

ATHENS (Reuters) - Greece's left-wing government has called a referendum for Sunday, July 5, after five months of acrimonious talks with its official creditors over an aid-for-reforms deal broke down without a deal.

Prime Minister Alexis Tsipras has said the plebiscite is not about Greece's membership of the EU single currency but a chance for Greeks to say whether they are willing to bear more austerity, demanded by the European Commission, the European Central Bank and the International Monetary Fund as part of a proposed deal.