Six retailers who are frustrated over their inability to compete on Sunday in the Tidewater, Va., area have banded together to challenge the state "blue law" that bars them from opening their doors on Sunday.

Best Products Co. Inc., Circuit City Stores Inc., Hechinger Co., K mart Corp., Roses Stores Inc., Zayre Corp. and Benderson Development Co. Inc., a real estate development firm, have filed a lawsuit in Virginia Beach Circuit Court to overturn the law.

The retailers charge that Virginia's blue law has been amended so many times to create exemptions for such a wide variety of businesses that the Sunday ban now only serves to discriminate against stores that have been unable to win exemptions.

The suit argues that the purpose of the Sunday laws was to guarantee that state employes would get a day of rest on Sunday. However, it notes, because of the myriad of exemptions granted over the past decade, the law "does not assure a day of rest for at least 80 percent of the employes in the commonwealth of Virginia."

About three-quarters of Virginia's counties and individual cities require Sunday closings. The remaining 25 percent, including Arlington and Fairfax counties and the Cities of Alexandria and and Falls Church, have decided through referenda not to enforce the Sunday-closing law.

The retailers tried to win a similar exception in Virginia Beach -- one of the state's fastest-growing areas -- two years ago but failed in a countywide referendum. As a result, they say they now are turning to the courts to undo what they charge is a basic unfairness of the law.

Paul A. Sciortino, commonwealth's attorney for the City of Virginia Beach, last week expressed doubt that the retailers would have much success in their efforts. "The state Supreme Court, as recently as 1977 and with all of the exemptions noted in the lawsuit , found that the blue laws were not discriminatory and did not grant unequal protection," he said.

However, he noted, the suit is probably the only way for the retailers and developer -- all of which have their headquarters outside Virginia Beach -- to challenge the blue law before 1986, when another referendum can be held.

Sciortino said the last referendum lost by a margin of about 3 to 1, with local retailers, mall owners, church groups and civic associations strongly supporting the blue law.

The retailers argue that the law is unfair because exemptions permit food, drug and garden-supply stores to do business on Sunday, while Hechinger, K mart, Best and the others cannot do so -- even though they sell many of the same goods.

For example, the lawsuit points to a florist's store in Virginia Beach that also has a substantial inventory of hardware and plumbing materials -- all of which can be sold on Sunday. Yet a nearby Hechinger outlet selling identical hardware and plumbing goods, as well as garden supplies, must remain closed.

"The Virginia law is written and enacted in such a way that it selectively benefits certain kinds of business," said John Hechinger Jr., president of the Landover-based do-it-yourself chain that is trying to enlarge its presence in the Tidewater area. It has opened three stores in the area in the past eight years.

Complicating the situation is the recent decision by military base exchanges to open on Sunday in the Tidewater area. "The federal government is competing with private industry and putting private industry at a disadvantage," Hechinger said. "We finally got to the point where it's just not fair."

Hechinger Co. estimates that its Virginia Beach store loses $1.4 million a year in business because of the Sunday ban. In its stores in communities that have overturned the blue laws, Hechinger says that 18 percent of total sales are rung up on Sunday. Similarly, K mart estimates that its two stores in Virginia Beach lose a total of $100,000 in business each Sunday.

In addition, the retailers complain, the Rouse Co. project at the Waterside Mall development in Norfolk is permitted to remain open on Sunday -- on the grounds that it is a type of public celebration or festival. Yet nearby stores selling the same type of items are required by law to be closed.

Overall, the original seven companies in the suit estimate they lose at least $5 million a year in sales because of the Sunday ban. The seventh plaintiff, the Virginia Beach developer S. L. Nusbaum & Co. Inc., dropped out of the suit a day after it was filed.

Virginia's blue law dates back to 1779, when the state barred any labor or business on Sunday, "except work of necessity or charity." They are known as blue laws because of the color of paper used by Massachusetts Puritans to publish 17th-century morality ordinances.