Thousands of Greek civil servants walked off their jobs as a strike against the government's latest plans to cut public sector staff began on Wednesday.
The two-day strike, called by public and private sector umbrella unions ADEDY and GSEE, is regarded as the peak of a week-long wave of protests and rallies nationwide.
The move comes days before the "troika" of the European Commission, European Central Bank and International Monetary Fund lenders visit Athens to check what progress it has made on promised reforms.
Their assessment will pave the way for the disbursement of the next bailout tranche in October.
Unionists, such as ADEDY's head Odysseas Drivalas, warned of an escalation of strikes during a "long and heavy winter until troika leaves Greece."
In a bid to rein in the 600,000-strong civil service, the government planned to place some 25,000 civil servants on a so-called "mobility scheme," which involves a pay reduction before a transferral to other posts, or dismissal if another position isn't found within a year.
The scheme is a key part of the latest round of measures agreed with Greece's international creditors to overhaul civil services, cut costs and secure further bailout loans.
Critics of the plan say it leads to higher unemployment and poverty rates, and demonstrators believe the price Greek households are paying for the rescue loans is too high after waves of harsh salary and pension cuts and tax increases.
ADEDY members warned that the mass firing of civil servants for the first time in more than a century will have an impact on services, and will aggravate the problem of ailing social insurance funds.
The government says the current plan is the only credible solution to Greece's financial woes, assuring the country is on its way to primary surplus in coming months and will return to growth.