Greek retail stores opened on Sunday for first time under a new law introduced earlier this year as part of the efforts to liberalize the sector and boost growth in debt-ridden Greece.

Workers unions protested with a 24-hour strike and small rallies were held nationwide.

Stores across Greece remained closed on Sundays for decades with the only exception of two working Sundays ahead of the Christmas and New Year Eve holidays.

As Greece is undergoing a major reform process since 2010 to exit the acute debt crisis which brought the country to the brink of default, Sunday shopping rules changed and the number of "Sundays with open stores" increased to seven to include the Easter holidays and sales periods.

The first Sunday the law came into force during the first ever November mid-season sales period introduced this year in Greece (Nov. 1-9), Athens malls and commercial streets were packed with people. Some 90 percent of stores opened on Sunday, according to early estimates.

However, most Greeks visited and left stores without making purchases, President of the National Confederation of Greek Commerce (ESEE) Vassilis Korkidis noted.

Similar images have been reported from across the country, damping hopes for a much-needed boost in revenues to keep afloat thousands of stores struggling with a six-year deep recession.

Korkidis and ESEE members await the final results of the first "crash test" and a few more tests before concluding whether the Sunday opening will benefit the sector.

Small retailers who object to the change argue that the increased operational costs for small stores in particular will outnumber any small boost in sales.

"It is not an issue of whether customers can find time to shop, but whether they have the money to spend," baker Stelios Exarchos told Xinhua.

Retail workers unions which also oppose the measure add to the argument that under the heavy burden of recession, store owners will most likely not hire more personnel for the Sunday opening. They expect that current employees will be forced to work longer hours instead.

"Never on Sunday," read banners waved by protesters in central Athens and other cities in a reference to a 1960 Greek film which won an Oscar award for the same titled song.