Republicans on the House Appropriations Committee today dropped an effort to defund a new Federal Communications Commission rule that will make political ad data available on the Internet.

The FCC rule, which was OKed by the commission earlier this year and is expected to go into effect sometime this summer or fall, would require TV stations to put detailed records on political ad buys on a new Web site. The files are currently public but are kept on paper at stations.

The broadcast industry has vigorously fought the rule. Earlier this month Rep. Jo Ann Emerson, R-Mo., chair of an appropriations subcommittee, added an amendment to a bill that would have blocked the FCC from using any funds to implement the transparency measure. The defunding amendment passed the subcommittee on a party-line vote.

The maneuver to defund the transparency rule attracted media attention and sparked outrage from outside public interest groups and Democrats.

But in a full committee hearing this morning, the Republicans backed down. Emerson offered a new amendment that removed the defunding language.

Under the revised bill, which passed the committee on a voice vote with bipartisan support, the General Accountability Office will simply conduct a study of the effect of the political ad rule on the TV ad sales market. The GAO will also look at the costs to broadcasters of putting political ad files online, which media companies have argued would costly.

The amendment requires the FCC to report to the committee on its response to the GAO study, which is due by July 2013.

Broadcasters are still fighting the FCC rule, which will not go into effect until the completion of a government review. The companies have sued in federal court to block the rule and also filed an appeal at the FCC.

Emerson, the subcommittee chair, did not immediately respond to our request for comment.

A Democratic aide on the Appropriations committee aide told ProPublica that the increasing attention on campaign finance after Citizens United made it difficult for Republicans to oppose the FCC’s transparency rule.  

“The backstory is that the majority thought they would slip this language in and no one would make a ruckus over it,” the aide said. “I don’t think the staff quite realized what they were getting into.”