Called by the largest private and public sector unions, the strike left ships docked at port, disrupted public transport and kept civil servants and journalists off the job.

Greece's largest labor union, the private sector GSEE, said the reforms, now pending approval in parliament, were the "last nail on the coffin" for workers and pensioners who have sacrificed enough after six years of austerity.

"They are trying to prove to the Eurogroup that they are good students but they are destroying Greece's social security system," a GSEE official said, referring to euro zone finance ministers who are due to meet on Monday.

Athens hopes the measures, due to be voted on in parliament on Sunday, will help persuade creditors to approve the release of bailout cash.

A tranche of about 5 billion euros is overdue, after talks faltered over the pace of reforms. The Eurogroup is expected to discuss the stalemate on May 9.

Prime Minister Alexis Tsipras, elected last year on an initial anti-austerity pledge but who was later forced to sign up to Greece's third international bailout since 2010, has a thin majority with 153 lawmakers in a 300-seat parliament.

Greece needs the bailout funds to pay IMF loans, ECB bonds maturing in July and growing state arrears, subject to lenders signing off on a review in its reform progress that includes changes to its tax and pension laws.

The proposed legislation would raise social security contributions, increase income tax for high earners and introduce a new national pension. It would also gradually phase out a top-up pension for low income earners.

Worn by years of austerity, Greeks fear that the new reforms will push the country further to the brink.

"We don't have food to eat and nobody asks us how we are," said shopkeeper Anna Papadopoulou, 74, who wept as she spoke.

Asked what she wanted to tell the Greek government, she said: "Wake up. We are dying."