Four farmers and two organizations are suing the state over a wheat checkoff increase approved by state lawmakers earlier this year.

Jim Teigen, of Rugby, one of the plaintiffs, said the lawsuit filed in South Central District Court in Bismarck argues that a portion of the increase that is earmarked for the private North Dakota Grain Growers and U.S. Durum Growers associations is unconstitutional.

"Certainly there are some questions of … the inability to have good legislative oversight of the expenditure of those funds," Teigen said.

The North Dakota Wheat Commission oversees the checkoff money collected from farmers when they sell grain. Commission Chairman Harlan Klein said Sunday that he was not aware of the lawsuit.

The Wheat Commission, a state agency, concentrates mostly on wheat marketing and promotion. It contracts with the private Grain Growers and Durum Growers for domestic policy lobbying work.

During the 2005 Legislature, lawmakers approved increasing the checkoff from a penny a bushel to 1.5 cents. At least two-tenths of a cent were designated for payments to the two commodity groups. The lawsuit estimates that the two-tenths of a cent would generate about $1 million over two years.

Some farmers testified during hearings that their tax money should not be earmarked for private groups with policies that some farmers do not support.

"We were very public about the opposition to it. We questioned the constitutionality of it," said Richard Schlosser, vice president of the North Dakota Farmers Union. Farmers Union is a plaintiff in the lawsuit, along with the Dakota Resource Council, a state environmental group.

The lawsuit states that Farmers Union and the Dakota Resource Council, as well as other groups, are capable of performing some or all of the services for which the Wheat Commission contracts with the Grain Growers and Durum Growers.