Several thousand protesters gathered outside Greece's parliament to mark May Day, and unions braced for more austerity measures imposed by bailout lenders.
Two large union-organized rallies are planned in Athens on the holiday, with employees at many public services nominally on strike.
As the marches began, government officials prepared for more talks at a central Athens hotel with representatives of bailout creditors as the two sides were near an agreement to maintain draconian spending controls beyond the current rescue program.
The talks had been expected to end Sunday. Future spending cuts will include additional pension cuts and tax increases for Greeks, already hit by seven years of harsh cuts.
Greece's largest labor union, GSEE, has called a general strike for May 17 to protest the latest austerity package. [AP]