Restaurants want to buy more liquor from Costco Wholesale and other retailers, and they think the Washington State Liquor Control Board is getting in the way.

That's one reason the parties that wrote and supported Initiative 1183, a voter initiative that privatized liquor sales in Washington, are suing the liquor-control board over the board's interpretation of the new law.

In particular, the Washington Restaurant Association, the Northwest Grocery Association and Costco disagree that restaurants can buy only 24 liters a day of wine and spirits from a retailer, according to a lawsuit filed Thursday in Thurston County Superior Court in Olympia.

The voter initiative said "no single sale may exceed" 24 liters, and the liquor-control board interpreted that as a "per day" rule.

In a release, the board called the plaintiffs' message "one-sided and inaccurate" and said it is "confident in the rules drafted to implement I-1183." It said those rules were written with advice from a state senior assistant attorney general.

The groups that backed the voter measure say small businesses are being hurt by the 24-liters-a-day rule and other interpretations of the law, including restrictions on delivery locations for spirits distributors, imposition of what they consider an unauthorized fee on certain spirits manufacturers, and what they're calling discrimination against foreign spirits producers' ability to market their products.

The new rules "chiefly benefit two large, out-of-state distributors," the coalition said in a release. In Washington, two distributors — Southern Wine & Spirits and Young's Market — dominate the market.

But John Guadnola, executive director of the Washington Beer & Wine Distributors Association, said his trade group thinks the rules, as adopted by the board, are "reasonable and, in fact, are required by the language of the initiative."

In its release, the liquor board rejected the plaintiff's claims the rules resulted from a board bias against I-1183 and that those rules have resulted in high liquor prices.

Liquor prices are higher because of new fees the measure imposes on distributors and retailers, the board said. And the board was neutral on the voter measure and successfully defended a lawsuit against it.

In writing the new liquor rules, the board said, it "took extraordinary steps in order to be inclusive of all impacted parties, including the plaintiffs. Unfortunately, there are many different financial relationships that are impacted by I-1183. What benefits one entity is likely to negatively impact others."

Melissa Allison: 206-464-3312 or mallison@seattletimes.com.

On Twitter @AllisonSeattle.