The U.S. Justice Department and some 20 states have endorsed a lawsuit that seeks to overturn an animal-rights measure passed in 2018 by California voters.

The measure, Proposition 12, mandates minimal living standards for animals used in agriculture. This year, provisions are scheduled to go into effect that require veal and eggs sold in California to come from calves and hens allowed, respectively, 43 square feet and one square foot of living space. Beginning in 2022, breeding sows must be provided at least 24 square feet of space, and hens must not be caged at all.

Industry trade groups, led by the North American Meat Institute, sued in federal court to overturn Prop 12, arguing that mandating in-state standards for companies with national distribution violates the Commerce Clause of the U.S. Constitution. Federal judge Thomas Whelan dismissed the case in April, ruling that “there is no burden on interstate commerce merely because [complying with Prop 12] is less profitable than a preferred method of operation.”

A panel of the Ninth Circuit Court of Appeals upheld the dismissal. The plaintiffs are appealing to the full panel to overturn it. The U.S. Justice Department filed an amicus brief in the case, which argues that “this ruling disregards Supreme Court precedent establishing that a State may not regulate extraterritorial conduct in order to prevent a harm—here, animal cruelty—that occurs entirely outside its borders.” Another amicus brief was filed by the States of Indiana, Alabama, Alaska, Arkansas, Georgia, Iowa, Kansas, Louisiana, Missouri, Montana, Nebraska, North Dakota, Ohio, Oklahoma, South Carolina, South Dakota, Texas, Utah, West Virginia, and Wyoming.

“The support from the United States government and 20 states underscores the significance of our case against Prop 12,” Julie Anna Potts, president and CEO of the Meat Institute, said in a statement. “Prop 12 is unconstitutional and not only hurts consumers with higher prices for pork, veal and eggs, it is costly for the federal government’s programs designed to help those facing hunger.”