Four lobbying groups representing some of the largest telecom companies in the country filed a lawsuit Wednesday opposing California’s net neutrality law in an attempt to stop it from going into effect next year.

The four industry groups filing the lawsuit were USTelecom, CTIA, NCTA, and the ACA —groups which represent telecom corporations like AT&T; Verizon Wireless; Charter Communications; and Comcast, and mobile companies like T-Mobile. This is the second lawsuit filed following the passage of California’s net neutrality law on Sunday. The first was fired off by the Department of Justice only hours after the bill received its final signature from Governor Jerry Brown.

Both lawsuits make similar claims that the California law is illegal due to a previous Federal Communications Commission ruling last year. That December ruling rolled back nationwide net neutrality protections, but also included a clause which preempted any net neutrality legislation from being put forth by the states.

“We oppose California’s action to regulate internet access because it threatens to negatively affect services for millions of consumers and harm new investment and economic growth,” the industry groups said in a statement. “Republican and Democratic administrations, time and again, have embraced the notion that actions like this are preempted by federal law.”

FCC Chairman Ajit Pai put out a statement alongside the Justice Department’s Sunday night announcement welcoming the lawsuit. “The Internet is inherently an interstate information service. As such, only the federal government can set policy in this area,” Pai said. “Not only is California’s Internet regulation law illegal, it also hurts consumers”

The California law won’t go into effect until January 1st, giving these groups and the Justice Department a little bit of time to make their case before ISP’s would actually be forced to abide by the new net neutrality protections. The law, championed by Sen. Scott Wiener, provides some of the strongest net neutrality protections in the country. It forbids ISP’s from blocking websites or throttling consumer data and even goes as far as prohibiting zero-rating programs.

Net neutrality advocacy groups, some of which helped get California’s law passed in the first place, obviously aren’t happy. Fight for the Future released a statement on Wednesday condemning both of the lawsuits. “It’s no surprise that they’re suing, but it does make it even more blatant and clear that Jeff Sessions and Ajit Pai are working directly on behalf of Big Cable in trying to block basic consumer protection legislation that passed with overwhelming bipartisan support.”

“Big telecom companies hate the California net neutrality bill because it prevents them from screwing over their customers more than they already do,” said Evan Greer, Fight for the Future’s deputy director.