Sobeys and Atlantic Superstore were in court Wednesday to challenge Nova Scotia's attempt to prevent more stores from openingSundays.

The grocery chains claim the provincial government has exceeded its authority and that its new Sunday shopping regulations are arbitrary and unfair.

"The level playing field for all grocery retailers is still the goal for Sobeys and we will pursue any and all options we have to achieve that," said Gerald Weseen, the company's senior director of communications in Atlantic Canada, before the hearing.

The province maintains that the government enacted the Retail Business Uniform Closing Day Act to ensure retail workers aren't forced to work on Sundays and that the cabinet can approve regulations as long as they conform to the spirit of the law.

"We have presented a very strong case that the government has the right to make regulations on behalf of the people and … that is what it did," said Cathy Shaw, director of communications for the Department of Finance.

Both sides presented their arguments before Justice Peter Richard in Nova Scotia Supreme Court.

The province tightened the rules on Sunday shopping in June by forbidding retailers from subdividing stores into smaller businesses, which Sobeys and Superstore had done to get around size restrictions.

In Nova Scotia, stores with more than 4,000 square feet of retail space are not allowed to open on Sundays, unlike boutiques, specialty stores and pharmacies.

Bedford grocer Pete Luckett subdivided his Pete's Frootique store in 1999, but Sobeys and Superstore only followed suit in June.

The two grocery giants were accused of violating the spirit of the Sunday shopping ban, and the government stepped in to close the loophole.

The lawyer for Sobeys, David Farrar, called that measure absurd, ridiculous and discriminatory, noting that the grocery store in Mabou, where Premier Rodney MacDonald shops on Sunday, is twice the size allowed under his own cabinet regulation.

PremierMacDonald said the results of the 2004 plebiscite on Sunday shopping had to be respected. In a close vote, Nova Scotians chose to maintain the status quo.

The court case is ofgreat interest to retailers in Nova Scotia, said Ross Haynes, the lawyer who successfully argued in 1999 that Pete's Frootique could legally open.

"Many people who make huge investments in our community, retail businesses, they probably want to see their businesses open as many days as possible to be more competitive and more profitable," said Haynes.

But he said this latest court challenge could end up tightening the Sunday shopping ban by erasing all exceptions.

"If they're successful and the court says the regulations are struck down in their entirety, it creates a lot of confusion because then you have to just read the act, and the act is pretty restrictive in what kind of businesses can be open," Haynes said.

The two sides areset to wrap up their presentations Thursday morning. It is not known when a decision will be rendered.