OLYMPIA, Wash. (Legal Newsline) -- The Washington State Farm Bureau and a handful of other business groups have filed a lawsuit seeking to reverse an increase in the state's minimum wage.

The minimum wage will increase by 12 cents an hour to $8.67 starting next year.

According to The Olympian, Attorney General Rob McKenna plans to bring in outside counsel on contract to defend the state Department of Labor and Industries, which set the higher rate.

The plaintiff in the suit is listed as the Kittitas County Farm Bureau. The business groups include the state Farm Bureau, the Washington Restaurant Association, the Washington Retail Association and the Washington Food Industry Association.

The attorney general's office issued an opinion in September saying the state did not need to increase the minimum wage, but Labor and Industries chose to adjust it based on other legal advice it received.

In 1998, state voters approved Initiative 688, which ties yearly minimum wage adjustments to boosts in the Consumer Price Index, or CPI.

At issue, according to the lawsuit, is whether the law requires "an upward adjustment" in a minimum wage that the state Farm Bureau contends is already the highest in the nation.

In a statement released last Thursday, the Farm Bureau said it is hoping for a court ruling that will freeze the rate hike before Jan. 1.

The bureau argues the decision to increase the minimum wage is "inconsistent with state law."

It said last year, when the CPI decreased, the state did not drop the minimum wage. This year, when the index increased, the attorney general's office was asked what to do.

The bureau contends McKenna's opinion was "clear," that the law requires the state "to hold the wage constant when CPI declines, but to consider those decreases when inflation kicks in again. The result would be no increase in the wage in 2011."

Scott Dilley, the bureau's policy analyst for labor issues, said in a statement that the wage hikes will cost jobs and slow the economy.

"Changes in the minimum wage have a direct impact in various industries and on more than just entry-level jobs," he said.

"The minimum wage increase isn't just about paying high school students more money to work at fast food restaurants. It is about the overall competitiveness of Washington industry. With the highest minimum wage in the nation, how long can our businesses remain competitive?"