Metro workers on strike in Athens for eight days risked being fired, the Greek government said Thursday.
The strike to protest pay cuts caused traffic jams and hampered access to airports.
Workers stayed away from their jobs despite a court decision at the start of the week deeming the protest action illegal.
Transport Minister Kostis Hadzidakis said after an emergency meeting that the government was imposing a civil mobilisation measure that allows it to fire workers who refuse to end the strike.
The city's electric railway, trams and buses were also not in service for most of the day after workers walked off the job.
Metro workers said they were protesting a unified pay structure the government is planning for civil servants, which would result in the abolition of their collective labour agreement.
The government aims to reduce transport workers salaries from 97.7 million euros (130 million dollars) in 2012 to 74.6 million euros this year.
Average gross wages without overtime on the metro will fall from about 2,500 euros to 2,038 euros.
The government passed a new round of austerity measures in December to ensure it continues receiving bailout funds. - Sapa-dpa