A vigil by protesting truck drivers continues outside the Greek parliament.
A vote is expected today on a new law to open up the trucking industry to competition.
Demonstrations began outside the parliament yesterday and continued throughout the night.
Hundreds of riot police have been deployed.
Debt-laden Greece is facing international pressure to carry out deep reforms and make its economy more competitive.
The new law would slash the price of licences to own and operate trucks. Road freight is described as one of the most closed sectors in the country.
It is reported no licences have been issued for nearly 40 years and those in circulation are sold from person to person for hundreds of thousands of euros.