Greece says it expects a joint aid package from the European Union and International Monetary Fund will be in place by the start of May. But there are calls of caution from within the EU. Germany for one said it would back a bailout package because the euro's stability was at stake, but that Greece would first have to prove it was pressing ahead with its deficit cuts. The Greek finance minister has been in Washington for a meeting of the International Monetary Fund, and warned speculators against betting on a default by Athens, saying they'd "lose their shirts".