Prime Minister George Papandreou of Greece has urged the country to accept austerity measures to avoid financial meltdown.
During an address to parliament, he said the economic measures that must be taken are needed for the country's survival and future.
Greece is in discussions with European Union and International Monetary Fund officials on a rescue package. Some reports suggest agreement could be reached this weekend.
Public sector unions say spending cuts will affect the poor disproportionately.
The Centre for European Studies in Brussels says 30% of Greece's GDP is spent on social security and pensions.
The aid package being offered by the EU and IMF is currently 45 billion euros ($US59 billion).
However, there are reports in Germany that the total cost of the proposed package could be up to 120 billion euros over three years.
Greece was previously bailed out by the EU in 1987 and reforms were promised, but not delivered.
The BBC reports the country is facing its worst economic crisis since a civil war, 60 years ago.
Crisis could spread - IMF
The head of the International Monetary Fund warned this week that the crisis in Greece could spread throughout Europe.
Managing director Dominique Strauss-Kahn said that every day lost in resolving Greece's problems risks spreading the impact "far away".
Concerns about the Spanish and Portuguese economies intensified after Standard & Poor's downgraded its rating on Greek debt on Tuesday, to "junk" .
Standard & Poor's also downgraded Spain's debt to AA from AA+ on Wednesday.