Two food distributors and a restaurant owner in the Los Angeles area have sued the state of California to overturn its new ban on the feeding practices used in the production of foie gras.

On July 1, a California law became effective that bans the method by which foie gras, a type of duck or goose liver, is made. The law specifically makes it illegal to “force feed a bird for the purpose of enlarging the bird’s liver beyond normal size,” and imposes penalties of up to $1,000 per violation and $1,000 for each day that violation continues.

The law defines “force feeding” as forcing a bird to “consume more food than a typical bird of the same species would consume voluntarily.” It also prohibits the sale of products in California that are the result of forced feeding.

The law’s proponents claim that “gavage,” the practice of forced feeding through a tube inserted into a bird’s gullet, is cruel. The law’s opponents claim that the practice is similar to natural pre-migration gorging and doesn’t harm the birds.

In a suit filed on July 2, Hot’s Restaurant Group Inc., which operates Hot’s Kitchen in Hermosa Beach and Hot’s Cantina in Northridge; and two distributors, Hudson Valley Foie Gras in New York and the Association des Eleveurs de Canards et d’Oies du Québec in Canada, allege that the ban is impermissibly vague and violates both the due process and commerce clauses of the U.S. Constitution.

They claim they have been forced to stop distributing or serving foie gras and collectively are losing $100,000 in sales each week as a result.

“In practice, the vagueness of this purported standard makes it impossible for anyone to know at what point a particular bird has been fed ‘more food,’ than” the law allows, the suit says.

“If this law remains in effect…then California will become the only place in the world where the sale of, for example, foie gras — and every other product that is ‘the result of’ ducks raised for their livers, including duck breast, duck fat, and even duck feathers — would be banned within its borders.”

Plaintiffs’ attorney Michael Tenenbaum, a solo practitioner in Thousand Oaks, Calif., did not return a call for comment. Lynda Gledhill, a spokeswoman for the attorney general, declined to comment.

The plaintiffs seek preliminary and permanent injunctions against enforcement of the law. In a July 5 brief, they said they were losing a combined $11,000 a day. The case is pending before U.S. District Judge Stephen Wilson in Los Angeles.

“Until this Court rules on the merits of Plaintiffs’ Due Process claims, no one in California can know if their sale or purchase of any duck or goose product — or the product of any ‘bird,’ for that matter — is legal,” the brief says.

Two years ago, a California appeals court tossed out a poultry supplier’s breach-of-contract lawsuit against Whole Foods Market Inc., which had stopped selling foie gras in 1996, concluding that the dispute lacked sufficient ties to California to proceed in that state’s courts.

Contact Amanda Bronstad at abronstad@alm.com.