Greek consumers hit by price increases since the introduction of the euro are boycotting shops in protest.
After consumer protection groups called on the public not to spend "a single euro on the market," many stores remain empty, with early reports indicating business is down by about 70 per cent at many shops.
The boycott is also scheduled to extend to public utilities, with consumers urged to switch off electricity and abstain from telephone calls for two minutes at 10pm.
Public transport workers joined the protest by giving passengers free rides for one hour beginning at 3pm, while restaurant owners planned to offer their dish of the day at cost price.
An opinion poll indicated 72 per cent of Greeks approved of the boycott, with 70 per cent saying they felt prices of goods and services had risen dramatically.
Finance Minister Nikos Christodoulakis has complained that retail businesses have fuelled inflation by rounding up prices following the adoption of the euro.
He has threatened to publish lists of companies accused of overcharging so that consumers "can know which businesses to boycott," and said such companies will be strictly audited by tax police.
PA