Truck drivers clashed with police in Athens on Wednesday in front of the parliament buildings where they have been staging a protest for the last 24 hours, just after the bill they oppose was passed.
Truckers threw stones and sticks at police as they charged a police cordon in an attempt to enter the chamber.
Police responded with pepper spray and other chemicals.
Truckers were reacting after Greek MPs voted through in principle a bill that will reform the trucking sector. Out of 99 votes, 83 voted for the bill while 16 voted against.
Drivers have refused to return to work for the last ten days, opposed to government plans that will make it easier to enter their trade.
The government says it will not back down on the bill.