The U.S. Federal Communications Commission should delay its scheduled May 15 vote on a new net neutrality proposal because of public outcry that the rules aren't strong enough, a commissioner said.

Commissioner Jessica Rosenworcel joined the dissenting voices of FCC Chairman Tom Wheeler's fellow Democrats when she called Wednesday for a delay in the scheduled vote to release Wheeler's net neutrality proposal and seek formal public comment.

On Thursday, Republican Commissioner Ajit Pai also called for a delay in the net neutrality vote. "I have grave concerns about the Chairman's proposal on Internet regulation and do not believe that it should be considered at the commission's May meeting," he said in a statement.

With a robust debate over the proposal already underway, the FCC should delay the vote for at least a month, Rosenworcel said Wednesday during a speech before the Chief Officers of State Library Agencies. Rosenworcel said she has "real concerns" about Wheeler's proposal, which would allow broadband providers to engage in commercially reasonable traffic management and, in some cases, allow providers to charge Web services for priority traffic arrangements.

Wheeler's proposal "has unleashed a torrent of public response," Rosenworcel said. "Tens of thousands of emails, hundreds of calls, commentary all across the Internet. We need to respect that input and we need time for that input."

There is some urgency for the FCC to reinstate net neutrality rules after an appeals court threw out an old version of the agency's rules in January, but "I think the greater urgency comes in giving the American public opportunity to speak right now, before we head down this road," Rosenworcel said.

Rosenworcel's speech came on the same day that more than 100 Web-based companies and advocacy groups, including Google, Facebook, Amazon and eBay, sent a letter to the FCC saying Wheeler's proposal, as described in early reports, represent "a grave threat to the Internet."

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 said.

Several Democratic lawmakers have also objected to the proposal. This week, Senator Al Franken, a Minnesota Democrat, joined the Progressive Change Campaign Committee's NoSlowLane.com campaign, saying Wheeler's proposal would divide the Internet up into a fast lane and slow lane.

"Net neutrality is under threat as it never has been," Franken said in a video. "This means that big corporations will be able to get their content delivered faster. Mom-and-pop stores would lose even more ground to corporate giants."

Representative Anna Eshoo, a California Democrat, said Wednesday the reaction against Wheeler's proposal has been "like a prairie fire." Wheeler's proposal to allow commercially reasonable traffic management on a case-by-case basis leaves "room for a great deal of mischief," she said.

Eshoo said she supports Rosenworcel's call for a delay during a Google hangout about the proposal.

Grant Gross covers technology and telecom policy in the U.S. government for The IDG News Service. Follow Grant on Twitter at GrantGross. Grant's email address is grant_gross@idg.com.