Unions opposing austerity measures in Greece are staging their fourth general strike this year as the government prepares to start cutting public sector jobs.
The walkout is disrupting flights, public transport, state hospitals and other services, while demonstrations are planned throughout the day.
The public sector has so far been spared from the job cuts that have hit the rest of the Greek economy since the country got its first international bailout in 2010.
However, the government has been forced to launch the cuts so it can continue receiving rescue loans from the International Monetary Fund and the other countries using the euro.
Parliament is set to vote on the new measures on Wednesday.
Several thousand protesters, most wearing caps to shield themselves from the midsummer heat, joined a peaceful march to parliament. More demonstrations are planned later in the day, while local government offices remain closed for a second day.
“The government ... is using the bailouts as an excuse to get rid of any labour rights we have left,” construction worker Costas Lavretzos said.
The government has been forced to axe 15,000 jobs by the end of 2014 and transfer 12,500 more this year.
“It’s a disgrace for the government to say that things are getting better with unemployment at such a high level. It is clear that with the economy still shrinking that we need a change of course,” Efklidis Tsakalotos, an MP from the left-wing main opposition party Syriza told parliament.
“The people running this country live in a different environment. They go to different hospitals. Their kids go to different schools. And they don’t understand what people are going through.”
Formed after elections last summer, the conservative-led government lost a junior coalition partner last month following a sudden decision to shut down state broadcaster ERT.
"The general strike is unlikely to succeed in its aim of forcing the government to withdraw its latest reform bill or convincing enough MPs to vote against it," said Martin Koehring, an analyst at the Economist Intelligence Unit.
“(But it) once again demonstrates the strong anti-austerity sentiment among the population.”