Trade unions in Greece have begun a 48-hour general strike, hours after the Prime Minister George Papandreou urged parliament to back an austerity package.
Huge crowds of protesters are expected on the streets of Athens, while public transport is set to grind to a halt.
The strike will disrupt or halt most public services, with doctors, ambulance drivers, journalists and even state-funded actors taking part, the BBC reports.
Airports will be shut for hours at a time, with air traffic controllers walking out, and ferries, buses and trains will also stop running.
The unions are angry that the government's austerity programme will impose taxes on those earning the minimum wage, following months of other cuts which have seen unemployment rise to more than 16%.
"These measures are a massacre for workers' rights. It will truly be hell for the working man. The strike must bring everything to a standstill," Thanassis Pafilis, a Greek Communist Party MP, said.
On Monday, Mr Papandreou said only his €28 billion austerity programme would get Greece back on its feet.
If the government loses, the European Union and IMF could withhold €12 billion 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.
More than 5000 police officers are due to be deployed in the centre of Athens on Tuesday, when tens of thousands of striking workers are expected to march towards parliament at 10am local time.