Technology giants Google and Facebook have joined forces with start-ups to criticise US plans to alter net neutrality rules.
The principle that all internet traffic should be treated equally was enshrined in US law in 2015.
But telecom companies complained an overly regulated net stifled innovation, particularly their ability to roll out broadband services.
Regulators will vote in December on whether to overturn the rules.
The changes have been proposed by the Federal Communications Commission, whose chairman Ajit Pai was a fierce critic of the Obama-era changes.
Facebook said: "We are disappointed that the proposal announced this week by the FCC fails to maintain the strong net neutrality protections that will ensure the internet remains open for everyone.
"We will work with all stakeholders committed to this principle."
In its statement, Google said the current rules "are working well".
Meanwhile, content giant Netflix tweeted: "This current draft order hasn't been officially voted, so we're lodging our opposition publicly and loudly now."
And, in an open letter to the FCC, a group, made up of 1,000 small businesses from around the US, wrote: "The success of America's start-up ecosystem depends on more than improved broadband speeds.
"We also depend on an open internet - including enforceable net neutrality rules that ensure big cable companies can't discriminate against people like us.
"We're deeply concerned with your intention to undo the existing legal framework.
"Without net neutrality, the incumbents who provide access to the internet would be able to pick winners or losers in the market.
"They could impede traffic from our services in order to favour their own services or established competitors."
The FCC asked the public to contribute to the debate around the rule changes and received a record 22 million responses.
But, in a press conference after it announced plans to change the rules, it said there had been many spam entries and therefore it had not taken the quantity of comments into account.
Telecoms companies, for their part, have said they would not use the rule change to start charging some content providers more for access to consumers.
In a blog post, ComCast's chief diversity officer wrote: "Comcast has already made net neutrality promises to our customers, and we will continue to follow those standards, regardless of the regulations in place."