California has been taken to court by 17 US states over a new state measure intended to curb single-use plastic and increase recycling.
The case was filed in federal court in Sacramento.
The states, all represented by various Republican attorneys-general, said California is attempting to "impose its own policy preferences on the entire nation" through the Plastic Pollution Prevention and Packaging Producer Responsibility Act.
Democratic Governor Gavin Newsom signed the measure into law in 2022.
Under the law, producers must cut single-use plastic in packaging and food service items by 25% while ensuring those items are recyclable or compostable by 2032.
Led by Nebraska, the states said the measure breaches the US Constitution’s Commerce Clause because it places a substantial burden on interstate commerce.
They also said the law would lead to higher consumer prices, with lower-income Americans likely to be hit hardest, as producers pass along the "extremely expensive" costs of changing a wide range of products and business practices.
In a statement, Nebraska attorney-general Mike Hilgers said: "Once again, California is trying to enact a policy that negatively impacts the rest of the country.
"If California goes unchecked, consumers will be forced to pay more for basic necessities."
The National Association of Wholesaler-Distributors is also listed as a plaintiff.
Those named as defendants include Zoe Heller, director of the California Department of Resources Recycling & Recovery, and the Circular Action Alliance, a "producer responsibility organisation" responsible for carrying out the law.
The nonprofit said it is also the only such organisation in Colorado, Maryland, Minnesota, Oregon and Washington.
Plaintiffs contend that California provides limited supervision even though the Alliance can require businesses to pay fees totalling as much as $500m each year as a condition of participating in the California market.
The suit asks a court to block implementation of the law and to declare that it conflicts with both the US Constitution and the California Constitution.
