"One of my concerns is that this policy statement is actually a back-door attempt to undermine the FCC's Open Internet rules, and hamstring the Commission's ability to manage the IP transition," said Rep. Henry Waxman (D-Calif.), the ranking member of the full Energy and Commerce Committee.
Republicans have sought to repeal the FCC's net neutrality regulations, formally called the Open Internet rules, since they were enacted in late 2010. They argue the rules unnecessarily burden businesses, but Democrats claim the rules are critical for protecting competition and consumer choice online.
Waxman warned the legislation could also undermine efforts to combat online copyright infringement, child pornography and foreign cyberattacks.
Rep. Anna Eshoo (D-Calif.), the subcommittee's ranking member, said officials from the FCC and the State, Commerce and Justice Departments have "expressed significant reservations" with the language of the bill.
She said Democrats will offer amendments at Thursday's mark-up to address their concerns.
Democrats and Republicans united last year to unanimously approve a non-binding resolution that encouraged U.S. delegates to an international telecommunications treaty conference in Dubai to fight proposals that would result in global Internet regulation.
Republicans insisted that the bill under consideration on Wednesday would only elevate last year's resolution into official policy.
"Last Congress, we 'talked the talk' and passed a resolution defending a global Internet free from government control. This Congress we must 'walk the walk' and make it official U.S. policy," Walden said. "If this is a principle we truly believe in, there is no downside to stating so plainly in U.S. law."
Eshoo expressed dismay that Walden never responded to a letter she sent outlining her concerns about the bill.
"No has sat down to meet with us," Eshoo said. "That doesn't serve us well."