Around 100 Communist Party supporters blocked the entrance to Greece’s Labour Ministry on Tuesday, to prevent international finance officials from getting into the building.
The so-called troika team are in Athens to review the progress of structural reforms being made in return for a multi-billion euro bailout.
On Monday, inspectors rejected part of the government’s new 12 billion euros in planned savings calling for a “bolder plan”.
Prime Minister Antonis Samaras has had to go back to his junior coalition partners to find additional cuts.
Meanwhile finance ministry data reveals that Greece’s deficit has been cut by 34 percent in the first eight months of the year.
But tax collection has fallen about two billion euros short of bailout targets.
Without the troika’s final approval of additional public spending cuts, a further 32 billion euro tranche of bailout funds are unlikely to be released.