Trade unions in Greece have begun a 48-hour general strike, hours after PM George Papandreou urged parliament to back an austerity package, BBC reported.
Huge crowds of protesters are expected on the streets of Athens, while public transport is set to grind to a halt.
On Monday, Mr Papandreou said only his 28bn-euro (£25bn) austerity programme would get Greece back on its feet.
If the government loses, the EU and IMF could withhold 12bn euros of loans and Greece could run out of money in weeks.
French President Nicolas Sarkozy has said French banks are ready to offer new 30-year loans to Greece when its current debts fall due.
He said other European countries whose banks had lent money to Greece were considering the same model to help prevent a default. But the UK denied it was pressing banks to "take a haircut".