The US Department of Justice (DOJ) is set to file a lawsuit against California, just hours after the state introduced a new bill to protect net neutrality.

According to campaigners in favour of net neutrality, the new law will help ensure a free and open internet by preventing Internet Service Providers (ISPs) like Verizon and AT&T from creating “fast lanes” for firms who are willing and able to pay for their traffic to be prioritised.

Measures to protect net neutrality were first introduced under the Obama administration, however they were abolished in December by the Trump-era Federal Communications Commission.

“While the Trump administration does everything in its power to undermine our democracy, we in California will continue to do what’s right for our residents,” said California state senator Scott Wiener, who authored the net neutrality bill.

Net neutrality protests – in pictures Show all 5 1 /5 Net neutrality protests – in pictures Net neutrality protests – in pictures Lindsay Chestnut of Baltimore holds a sign that reads "I like My Internet Like I Like my Country Free & Open" as she protests near the Federal Communications Commission (FCC), in Washington, Thursday, Dec. 14, 2017, where the FCC is scheduled to meet and vote on net neutrality. The vote scheduled today at the FCC, could usher in big changes in how Americans use the internet, a radical departure from more than a decade of federal oversight AP Net neutrality protests – in pictures Demonstrators rally outside the Federal Communication Commission building to protest against the end of net nutrality rules December 14, 2017 in Washington, DC. Lead by FCC Chairman Ajit Pai, the commission is expected to do away with Obama Administration rules that prevented internet service providers from creating differnt levels of service and blocking or promoting individual companies and organizations on their systems. Getty Images Net neutrality protests – in pictures Demonstrators rally outside the Federal Communication Commission building to protest against the end of net nutrality rules December 14, 2017 in Washington, DC. Lead by FCC Chairman Ajit Pai, the commission is expected to do away with Obama Administration rules that prevented internet service providers from creating differnt levels of service and blocking or promoting individual companies and organizations on their systems. Getty Images Net neutrality protests – in pictures Demonstrators rally outside the Federal Communication Commission building to protest against the end of net nutrality rules December 14, 2017 in Washington, DC. Lead by FCC Chairman Ajit Pai, the commission is expected to do away with Obama Administration rules that prevented internet service providers from creating differnt levels of service and blocking or promoting individual companies and organizations on their systems. Getty Images Net neutrality protests – in pictures Demonstrators rally outside the Federal Communication Commission building to protest against the end of net nutrality rules December 14, 2017 in Washington, DC. Lead by FCC Chairman Ajit Pai, the commission is expected to do away with Obama Administration rules that prevented internet service providers from creating differnt levels of service and blocking or promoting individual companies and organizations on their systems. Getty Images

The DOJ claims that the law passed by California governor Jerry Brown is an attempt to “subvert the federal government’s deregulatory approach” to the internet.

“Under the constitution, states do not regulate interstate commerce – the federal government does,” said attorney general, Jeff Sessions.

“Once again the California legislature has enacted an extreme and illegal state law attempting to frustrate federal policy. The Justice Department should not have to spend valuable time and resources to file this suit today, but we have a duty to defend the prerogatives of the federal government and protect our constitutional order.”

“California’s decision to fight this battle in the legislature also sets it apart from other states that have enshrined limited protections through a governor’s executive order, which can only dictate ISPs’ conduct in state contracts,” Hayley Tsukayama, a legislative activist at the Electronic Frontier Foundation (EFF), said in a blog post praising the new California law.

“Laws are also harder to reverse than executive orders, ensuring that these important consumer protections cannot be reversed in the future with the flick of a pen,” she said.

Ms Tsukayama said the EFF will keep pushing for pro-net neutrality legislation to be passed across the US.