The lawsuit was filed in US District Court for the Eastern District of California by mobile industry lobby CTIA; cable industry lobby NCTA; telco lobby USTelecom; and the American Cable Association, which represents small and mid-size cable companies. Together, these four lobby groups represent all the biggest mobile and home Internet providers in the US and hundreds of smaller ISPs. Comcast, Charter, AT&T, Verizon, T-Mobile US, Sprint, Cox, Frontier, and CenturyLink are among the groups' members.

"This case presents a classic example of unconstitutional state regulation," the complaint said. The California net neutrality law "was purposefully intended to countermand and undermine federal law by imposing on [broadband] the very same regulations that the Federal Communications Commission expressly repealed in its 2018 Restoring Internet Freedom Order."

ISPs say the California law impermissibly regulates interstate commerce.

The suit comes after the U.S. Justice Department on Sunday filed its own suit to block the new law. California Governor Jerry Brown signed legislation Sunday to restore open internet protections known as net neutrality in the state after the Trump administration repealed the rules in December 2017.

Like the DOJ, broadband lobby groups argue that state net neutrality laws are preempted by the Federal Communications Commission's repeal of federal net neutrality rules. The FCC and DOJ claim that California's net neutrality law conflicts with the federal government's deregulatory policy for broadband. California argues that the FCC gave up its authority to regulate broadband and therefore cannot preempt states from regulating the industry.

The new California state law prohibits Internet service providers from blocking or throttling lawful traffic and from requiring fees from websites or online services to deliver or prioritize their traffic to consumers.