Greece's main private sector union GSEE on Monday said it would stage a 24-hour general strike on April 9 to protest new labour reforms demanded by the country's EU-IMF creditors.
Athens is currently in talks with the creditors over the next instalment of funding from its multi-billion-euro bailout.
Loan payments to Greece worth some 8.5 billion euros ($11.8 billion) are pending.
According to reports, the creditors are pushing for additional civil service layoffs and changes to a 1982 law on strikes to reduce the frequency of labour actions.
Hard hit by the economic crisis, Greece is experiencing a sixth straight year of recession and has a staggering 28 percent unemployment rate.
Pharmacists have also staged successive two-day walkouts over plans to open up medicine sales in retail outlets other than pharmacies.
And an ongoing overhaul of the public health system has sparked strong opposition from state-employed doctors.
The so-called "troika" of the European Union, the European Central Bank and the International Monetary Fund first bailed out Greece in 2010 with a programme worth 110 billion euros.
When that failed to stabilise the economy, they agreed a much tougher second rescue in 2012 worth 130 billion euros, plus a private sector debt write-off of more than 100 billion euros.
Five general strikes were staged last year.