It started in Aphidnai, a small town north of Athens.
Local residents, angry at losing their exemption from paying tolls for using a 500m stretch of motorway, raised a banner saying “Den Plirono” (“I won’t pay”).
In the space of four months, Den Plirono has grown from a one-off protest to a nationwide anti-austerity movement.
Growing opposition to reform is unnerving markets and alarming Greece’s eurozone partners, whose leaders meet in Brussels on Friday.
“We’re a popular, not a political movement, taking a pro-active approach to the worst crisis in Greece since world war two,” said Konstantinos Dimitriades, a 30-year-old mini-market supplier and one of the founders of Den Plirono.
The movement’s supporters refuse to pay highway tolls. In Athens they ride buses and the metro without tickets to protest against an “unfair” 40 percent increase in fares.
So far, only a few protesters have been asked to pay fines, Mr Dimitriades said.
George Papandreou, the prime minister, has accused Den Plirono of running a civil disobedience campaign aimed at undermining economic reforms agreed in return for a bail-out by the European Union and International Monetary Fund.
Others say the movement highlights increasing reform fatigue as the “troika” – experts from the European Commission, the IMF and the European Central Bank – calls for more fiscal measures and a tougher approach to structural reform.
“More than ever, the next steps... require the government’s determination, political co-ordination and the consensus of Greek society,” the Commission said in its latest progress report.
The broadening support for Den Plirono suggests that consensus may be hard to achieve.
Greek salaries have shrunk by an average 20 percent since the EU-IMF program was launched last May. The jobless rate hit a record 14.8 percent in December. Inflation stood at 4.9 percent in January, more than double the eurozone average.
Mr Dimitriades said the group’s next move would be to tear up electricity bills, on the ground that tariffs had more than doubled since the recession started.
Greece’s state-controlled electricity utility already arranges payment by instalments for customers in low-income districts of Athens rather than cutting them off, according to its union.
Mr Papandreou is backed by opposition leaders in his attempt to win easier repayment terms for the bail-out loan at Friday’s summit.
But both the conservative and communist leaders have refused to support the EU-IMF programme.
“This programme is strangling the Greek economy... it needs renegotiation and radical change,” said Antonis Samaras, the conservative leader, on Tuesday.
Aleka Paparriga, the communist leader, said: “Worse measures are on the way... so obviously there can’t be consensus.”
Reform fatigue also appears to affect the socialist government, with legislation of structural reforms suffering delays or being diluted thanks to opposition by interest groups.
Greek media regularly carry reports of clashes at cabinet meetings involving high-profile ministers in charge of implementing key reforms.
“There’s a danger of ministers entering a midterm mindset that leads to slippage. Many of the cabinet are old-style politicians open to pressure from vested interests,” said one analyst.
Parliament has approved a long-awaited bill opening up more than 60 “closed-shop” professions. Yet the new law has been watered down, allowing powerful groups such as pharmacists and lawyers to keep privileges at odds with practices elsewhere in the EU.
“It’s disappointing because the opening up of these professions is critical to improving competitiveness in the medium term,” said Yannis Stournaras, director of Athens think-tank IOBE.
Parliament is due to approve this month a bill overhauling the tax administration that has been prepared with assistance from IMF experts.
It provides for setting up a special service to evaluate claims of tax officials’ involvement in bribe-taking and launching a three-year programme to combat tax evasion that includes benchmarks and measurable targets.
“This bill pushes the system forward, but it begs the question, will it be properly implemented?” said Nikos Karavitis, associate professor of fiscal policy at Panteios university.