Junior Greek coalition partner Democratic Left formerly declared on Thursday night that it will vote against labour reforms in a new cuts package next week.
It means the party will vote against the revised €13.5 billion (£10.8bn) austerity package being demanded by Greece's foreign creditors - the EU, IMF and European Central Bank - as a condition of continued loans.
Conservative Prime Minister Antonis Samaras formed the coalition government with the Socialists and Democratic Left after elections in June, commanding 176 seats in the 300-member parliament.
The loss of Democratic Left's 16 votes means nearly all of the socialists will have to say Yes to the cuts - despite wavering support in recent days.
Attacks such as yesterday's horrific murder in Woolwich didn't happen before the 'war on terror.' It's time we recognised the consequences of the conflicts we've unleashed