The strike will affect services, including schools, hospitals and public transport.
On Wednesday, a nationwide general strike will take in Greece.
GREEK trade unions have called a general strike for tomorrow as parliament considers European Union-dictated cuts stretching into the next decade.
Amid confirmation that the country's battered economy is in recession again, unions have launched a wave of protests ahead of a general strike on Wednesday. No newspapers will be circulating on Wednesday as journalists will put a pause on reportage on Tuesday.
Air traffic controllers were holding a four-hour work stoppage in the middle of the day, leading to the rescheduling or cancellation of more than 150 flights. Greek seamen are on a 48-hour to protest new austerity measures.More news: Trump asked Comey to shut down Flynn investigation
People are silhouetted under a fluttering Greek national flag atop the archaeological site of the Athens Acropolis, Greece, March 20, 2015.
The Greek government hopes that legislating new austerity measures by May 18 will allow its euro zone partners to approve the deal when they meet on May 22 and to release a new tranche of bailout funds.
Greece is now still struggling to secure a new bailout from worldwide lenders.
The latest round of measures will introduce pension cuts in 2019 and higher income tax in 2020, under an agreement with global bailout lenders for continued rescue funding.
Without the agreement with its creditors, Greece faced the prospect of running out of cash to service its debts this summer, which could have seen it have another brush with bankruptcy. In return for the money, the government promised to enact a series of austerity measures as well as economic reforms its progress is continually monitored by institutions from the European Union and the International Monetary Fund.