Greek police fired tear gas yesterday at hundreds of demonstrators trying to approach the finance ministry in a protest against austerity cuts to tackle the country's debt crisis, police said.

"Around 500 people were demonstrating and some of them tried to break through a police cordon guarding the ministry," a police source said.

The protest was called by the left-wing Syriza party after union leaders said the government was about to adopt additional austerity measures to clinch a huge bailout from the European Union and International Monetary Fund.

Clashes also briefly erupted as the protest passed in front of the Greek parliament, an AFP photographer said, with demonstrators throwing plastic bottles at police who fired more tear gas.

The demonstrators damaged a number of bus stops and garbage bins as they retreated.

The Socialist administration of George Papandreou has already enacted unprecedented spending cuts and tax hikes mainly targeting the public sector, angering unions who have staged a series of strikes and street protests.

Greece is holding crucial talks with the EU, the European Central Bank and the IMF on a loan which could run up to €120 billion over three years, shielding Athens from punishing market rates as it seeks to reduce a public debt of nearly €300 billion.

Senior trade union officials briefed by Mr Papandreou earlier in the day said the EU and IMF want Greece to save €25 billion in the next two years in return for the loans.

Athens was also asked to get rid of 13th and 14th month bonuses for public sector workers and pensioners and raise value-added tax, they said.

Greece's first urgent deadline is on May 19 when it must repay maturing debt worth nine billion euros.