Greek workers have taken to the streets for an anti-austerity protest ahead of a vote in parliament on sweeping pension reforms.
Flights to and from Greece are grounded, ferries are docked at ports and public offices are shut down, as unions stage their sixth 24-hour strike this year.
'We reject the pension reform bill, a bill that erases fundamental principles,' Yannis Panagopoulos, head of private sector union GSEE, said. 'We will not stop fighting.'
Some 12,000 people, according to police, marched through the capital with banners attacking the International Monetary Fund and the EU, which are involved in a loan bailout unpopular with many Greeks.
Another 5,000 had earlier demonstrated in the northern city of Thessaloniki, local police said.
The demonstrators accused Greek Prime Minister George Papandreou of shielding big business interests from bearing the brunt of state spending cuts, which have hit civil servants, private employees and pensioners.
Lawmakers are today debating a reform bill that curbs early pensions and raises the retirement age.
The reform is part of an austerity deal agreed with the EU and the IMF in return for a €110bn aid package to pull the country out of a severe debt crisis.
Greek lawmakers agreed in principle on the pension reform in a preliminary vote late yesterday.
It was a first sign that the Socialist government with 157 lawmakers in the 300-seat parliament was also likely to pass the reform during a final vote today, despite grumblings in its own ranks.
'We are carrying out the great structural reform of the pension system without considering the political cost. We must put an end to the years of false prosperity,' Labour Minister Andreas Loverdos said.
Parliament workers said they would also strike, in what is their first walkout in 25 years.
It was not immediately clear how this would affect the voting process.
About half of Greeks believe the pension reform is necessary, a poll showed last week.
Turnout at rallies on strike days has fallen, about 12,000 people marched in Athens in the last joint stoppage on 29 June, down from 50,000 in the biggest rally on 5 May, when three people died in the fire-bombing of an Athens bank.
Greece's private and public sector unions represent about 2.5m workers, or half the country's workforce.
