Greek police fired teargas and attacked 200,000 workers and youth outside parliament yesterday who were seeking to prevent MPs entering parliament to vote on new austerity measures.
The youth around Syntagma Square in Athens responded to the police attack by throwing yoghurt and stones.
Hundreds of thousands took part in a general strike, the third in Greece this year. Ports, public transport and banks were shut.
Police sealed off the roads leading to Syntagma Square and created a pathway for deputies.
The new austerity programme required for the EU and IMF bail-out package is for 28bn euros (£24.6bn; $40.5bn) in cuts to take effect from 2012 to 2015.
Papandreou faces the risk of a revolt in his own Pasok party over the plans.
State-run companies joined the walkout, while hospitals are only offering emergency care.
The demonstrators called themselves the ‘indignants’, after the Spanish anti-austerity protesters who set up camps in Madrid and Barcelona.
The square was awash with Greek and Spanish flags, as well as banners reading ‘Resist’ and the battle cry from the Spanish civil war, ‘No pasaran’ (they shall not pass).
One MP defected on Tuesday, leaving Papandreou with only 155 of the chamber’s 300 seats.
One other Pasok MP has threatened to vote against the cuts and privatisation of state assets. Another 14 are wavering in support.
Meanwhile, EU finance ministers meeting in Brussels have failed to reach agreement on how to make private creditors contribute to a second Greek bail-out without throwing financial markets into turmoil.
As a result of their failure to reach a deal, the cost of insuring Greek debt against default shot to an all-time high.