Greece's government ordered striking transport staff back to work on Thursday, threatening them with arrest if they refuse to end an eight-day walkout that has paralyzed the Athens subway.
Workers said they would defy the order, issued under emergency legislation the conservative-led government invoked for the first time since taking power in June.
The strike is the latest test for Greece's fragile coalition as it faces down the unions to implement austerity measures demanded by foreign lenders as the price for bailout funds.
"Neither the government nor society can be held hostage to union mentality," Development Minister Kostis Hatzidakis said after five hours of talks with Prime Minister Antonis Samaras.
"The government can't ignore this. There is nothing else we can do."
But in a sign of the coalition's fragility, the move was criticized from within its own ranks as the smallest party in the three-party government called it "extreme".
"At a time when society is under such pressure, every option to reach an agreement must be exhausted first," the Democratic Left party said in a statement. "Being uncompromising - on both sides - does not help."
Samaras, however, refused to back down.
"The Greek people have made enormous sacrifices and I will not allow exceptions. Transport does not belong to the unions - it belongs to the people and they have the right to use it," he said in a statement.
Public anger has grown against the strike which affects more than half a million commuters in the city of 5 million people. Some Athenians said their daily commute time had tripled and many were having to pay for costly taxi rides.
A hailstorm and a bus strike worsened disruptions during the Thursday evening rush hour, causing long queues for taxis and leaving crowds huddled under bus shelters.
"The workers are taking advantage of their union power while the ordinary commuter, who is unprotected, is being punished," said Antonis Demetriadis, 40, who works in a marketing company.
"Who is going to protect me? Would they care if my pay is cut?"
When the same emergency law was invoked against truck drivers in 2010, workers obeyed the order to return to work after a week-long strike that had disrupted fuel supplies and emptied gas stations. But the subway workers were defiant and other unions voiced their support.
"We will not back down, we will resist," one union leader, Antonis Stamatopoulos, told Reuters after addressing workers at a subway station in the working-class neighborhood of Sepolia.
Subway workers, who have defied a court order to return to work, oppose being included in a unified wage scheme for public sector workers that would slash their salaries.
"It's not that subway workers went crazy over the last eight days. We exhausted every possibility before going on strike. We've reached our limits. We've run out of patience," said Manthos Tsakos, general secretary of the metro workers' union.
Bus, railways workers and seafarers said they would walk off the job in the coming days in solidarity with subway workers as major unions expressed their support.
Greece's largest private and public labor unions GSEE and ADEDY, representing about 2 million workers, said they would hold a 24-hour strike in February to protest the government's belt-tightening policies.
"This government is out of control," said ADEDY General Secretary Ilias Iliopoulos. "Taking decisions that are usually taken in extreme political situations is absurd, especially in a country that gave birth to democracy."
Greece, kept afloat solely by foreign aid, averted financial collapse in December when its euro zone partners agreed to keep funds flowing but insisted on unpopular reforms that have driven up unemployment to record levels and fuelled anger against the government.
A poll by Pulse for To Pontiki newspaper on Thursday showed the radical leftist opposition Syriza would win with 24 percent of the vote if elections were held today, while Samaras's New Democracy party would trail with 22.5 percent.
(Additional reporting by Renee Maltezou and George Georgiopoulos; Editing by Deepa Babington and Robin Pomeroy)