U.S. communications regulators voted unanimously to support an open Internet rule that would prevent telecom network operators from barring or blocking content based on the revenue it generates.

The proposed rule now goes to the public for comment until Jan. 14, after which the Federal Communications Commissions will review the feedback and possibly seek more comment. A final rule is not expected until the spring of next year.

“I am pleased that there is broad agreement inside the commission that we should move forward with a healthy and transparent process on an open Internet,” FCC Chairman Julius Genachowski said.

The vote came despite a flurry of lobbying against the net neutrality rule by telecommunications service providers like AT&T Inc, Verizon Communications Inc and Qwest Communications International Inc, which say it would strip them of the ability to manage their networks effectively and would stifle innovation and competition.

The rule would prevent operators from discriminating against any legal content a third party wants to deliver to consumers on their networks, though it allows for “reasonable” network management to unclog congestion, clear viruses and spam, and block unlawful content like child pornography or the transfer of pirated content.

Advocates of net neutrality such as Google Inc, Amazon.com Inc and public interest groups say Internet service providers must be barred from blocking or slowing traffic according to how much revenue the content generates.

But service providers say the increasing volume of bandwidth-hogging services, such as video sharing, requires active management of their networks and warned of unintended consequences of such a rule (net neutrality).

Nonetheless, the vote was 5-to-0 for proceeding with the rulemaking, and 3-to-2 for approving the notice’s language in its entirety, said Jen Howard, an FCC spokesman.

The FCC will accept public comments until Jan. 14; then it will review them and can ask for further comment, with replies due by March 5.