More than 100 online firms including Google, Amazon and Facebook have signed a joint letter to the U.S. Federal Communications Commission warning of "grave consequences" if it fails to protect the openness of the Internet.
The letter cites reports that the FCC plans to propose watered-down net neutrality rules next week that will allow cable and phone companies to charge online firms fees to prioritize their traffic on the Internet.
Critics say those rules would create a two-tier Internet that penalizes smaller firms and allows companies that are able to pay to offer better services.
"If these reports are correct, this represents a grave threat to the Internet," says the letter, addressed to Chairman Tom Wheeler and the other FCC commissioners.
Also signed by eBay, Reddit, LinkedIn and other big names, the letter aims to persuade the FCC to toughen its stance on net neutrality.
The proposed rules would "enable phone and cable Internet service providers to discriminate both technically and financially against Internet companies and to impose new tolls on them," the letter says.
Instead of permitting "individualized bargaining and discrimination," the FCC should protect users on fixed and mobile platforms against "blocking, discrimination, and paid prioritization."
The letter highlights the apps and services created by "American innovators" used around the world, and says tougher rules are needed to ensure America "continues to lead the world in technology markets."
The FCC is expected to officially propose its new rules on May 15, which will be followed by a lengthy approval process.
The FCC insists its rules won't upend fairness of the Internet. ISPs (Internet service providers) won't be able to act in a "commercially unreasonable manner," it says, or block any legal content.
"To be very direct, the proposal would establish that behavior harmful to consumers or competition by limiting the openness of the Internet will not be permitted," Wheeler wrote in a blog post last month.
But the online firms are unconvinced.
"This Commission should take the necessary steps to ensure that the Internet remains an open platform for speech and commerce so that America continues to lead the world in technology markets," they wrote.