The US Department of Justice threw its weight behind telecommunications operators on Thursday, warning telecom regulators against imposing so-called ‘net neutrality’ rules that would block carriers from charging content providers premium prices to prioritise some web traffic.

While the ultimate decision over whether to impose new regulations on how broadband internet providers transmit and deliver internet traffic over their networks rests with the Federal Communications Commission, the Department of Justice’s comments represent a significant blow to content companies such as Google, Microsoft, Amazon and eBay.