Negotiations on forming a new Greek government is set to resume on Tuesday after three previous failed attempts.
The radical left block (Syriza) has refused to join any coalition which supports austerity in exchange for bailout packages.
The mainstream socialists have attacked the Left for their intransigence.
If the parties can't agree on a coalition there will have to be another election next month.
But if Greeks elect a parliament that is opposed to austerity policies it may lead to Greece's exit from the eurozone.
Al Jazeera's Tim Friend reports from Athens.