Four Democrats on a congressional panel called on regulators on Monday to press ahead with their own Internet traffic rules instead of relying on a proposal from two communications companies.
Julius Genachowski, chairman of the Federal Communications Commission, said any outcome or deal that does not preserve an open and free Internet for consumers and entrepreneurs would be unacceptable.
Last week, Verizon Communications and Google said regulators should be able to police Internet traffic over cable and telephone lines, but that carriers themselves should be able to control the speed of consumers' access to content on wireless devices such as smartphones and iPads.
The companies' joint proposal marked a surprising compromise on so-called "network neutrality," which refers to the concept that high-speed Internet providers should not block or slow information or make websites pay for faster ways to reach users.
Democrats Ed Markey of Massachusetts, Anna Eshoo of California, Mike Doyle of Pennsylvania and Jay Inslee of Washington, all members of the House Energy and Commerce Committee, sent a letter to Genachowski that said he should maintain a free and open Internet.
"Rather than expansion upon a proposal by two large communications companies with a vested financial interest in the outcome, formal FCC action is needed," they wrote.
FCC spokeswoman Jen Howard declined to comment on the letter.
Last October, the FCC issued a net neutrality proposal and collected public comments, but it has not said when it plans to implement it.
In its proposal, the FCC asked for public comment on if operators should be prevented from discriminating against any legal content a third party wants to deliver to consumers on their land line and wireless networks.
It would allow for "reasonable" network management to unclog congestion, clear viruses and spam and block unlawful content such as child pornography or the transfer of pirated content.