MADISON, Wis. (AP) — Wisconsin dairy farmers who believe they have found a way to legally sell raw milk in the state will make their case in court on Tuesday.

The operators of Grassway Organic Farm in Calumet County allege in a case before a Dane County judge that the state has no right to stop them from selling milk to customers who have become part-owners of the farm.

The case isn't a direct challenge to Wisconsin's ban on raw milk sales, but if Kay and Wayne Craig prevail, it would open up a loophole large enough to drive a herd of dairy cows through.

"Our entire system of licensing would be in jeopardy," said Cheryl Daniels, the food safety division attorney with the Wisconsin Department of Agriculture, Trade and Consumer Protection.

The Craigs' lawsuit is one of two in the court system related to the state law banning all but incidental sales of raw milk. Another one, involving Walworth County farm Nourished by Nature, was transferred on Thursday to Dane County and may ultimately be combined with the Craig lawsuit.

Access to raw milk has also led to controversy in Minnesota, where the Department of Health says at least eight people got E. coli from raw milk at a farm in Gibbon. Minnesota law allows incidental milk sales on farms, and the owner of the southwestern Minnesota farm in question has disputed its milk is at fault.

Officials said some of the Minnesota cases came from milk purchased through special clubs barred under state law.

The Farm-to-Consumer Legal Defense Fund, which is based in Virginia and advocates for raw milk sales nationally, is defending the farmers in both Wisconsin cases.

"There's still tremendous political pressure to not allow raw milk sales," said Kay Craig, who runs the organic farm about 70 miles north of Milwaukee in New Holstein with her husband Wayne. "We feel we're right and we feel that this is something we have to do. ... We're not hiding what we're doing."

Wisconsin's dairy industry joined forces with the Wisconsin Medical Society and other farm and health groups to oppose a bill in the Legislature to legalize on-farm raw milk sales for a little over a year.

Despite their opposition, the Legislature overwhelmingly passed it after hundreds of people came out in support at a massive public hearing in Eau Claire.

Gov. Jim Doyle vetoed the bill, citing the concerns of opponents about the dangers of consuming unpasteurized milk and what harm an outbreak could cause the state's $26 billion dairy industry.

Nineteen states allow direct sales of raw milk from dairy farmers to individuals. Another nine states allow retail sales.

The Craigs' filed their lawsuit in December, before the issue caught fire in the Legislature. They were motivated by DATCP's refusal to renew their license for operating the on-farm store, citing the sales of raw milk. The Walworth County lawsuit was brought in February.

Wisconsin law allows only incidental sales of raw milk that are not part of a farm's regular business and are not advertised.

The Craigs argue in the lawsuit that the state can't stop them from selling raw milk to customers who are part-members of their farm. It costs $10 to belong and the Craigs have about 300 members. They charge $6 per gallon of raw milk and sell about 260 gallons a week, Kay Craig said. That equates to more than $81,000 a year in raw milk sales alone.

Without those sales, which are made out of a bulk tank elsewhere on the farm, the store that offers other meat and dairy items would likely have to shut down, Kay Craig said.

"The raw milk sales really do drive the store," she said.

The state argues that it interprets state law to mean all raw milk sales are banned, except for incidental sales. And regular sales to hundreds of members goes far beyond incidental, the state contends.

"We believe that this idea of this members-only organization that can be outside the regulations is simply not available under Wisconsin law," said Daniels, the DATCP attorney.

The Craigs' filed the lawsuit seeking a ruling that they are not breaking the law by offering raw milk to the part-owners of their farm and that they can continue to do so. They are also seeking an injunction stopping the state from taking any enforcement action against them.

The state is seeking dismissal of the lawsuit, which Dane County Judge Patrick Fiedler has scheduled to rule on Tuesday.

Copyright 2010 The Associated Press.