The opponents of a new rule to post political ad information online have opened up another front in a long-running fight, inserting language into an appropriations bill that would bar the Federal Communications Commission from implementing the transparency measure.

The FCC voted in April to require television stations to put detailed data on political ad purchases online. The information, which includes who buys ads, for how much, and when they run, is currently open to the public but is available only on paper at individual stations. Media companies have lobbied hard against the rule, and the National Association of Broadcasters recently sued in federal court to stop it. The rule is currently under review by the government and will not go into effect until July at the earliest.

Rep. Jo Ann Emerson, R-Mo., chair of the financial services and general government subcommittee of the House appropriations committee, added language to an appropriations bill ordering that no funds to be used to implement the disclosure rule. The bill, which passed the subcommittee Wednesday, funds the FCC and other agencies for fiscal year 2013.

The move by Emerson adds another question mark to the process of creating an FCC website with political ad data. At a subcommittee hearing Wednesday, a Democratic amendment to remove the Emerson language was defeated on a party line vote.

"I suspect there will be a big fight in committee and on the floor," Rep. José Serrano, D-N.Y., who led the Democratic effort to defeat the language, told ProPublica.

He added that Democrats will try again to strip the Emerson language when the full appropriations committee considers the bill, which may happen in the next couple weeks.

"When there's a campaign going on with the kind of money that is being spent today," Serrano said, "you as a citizen should have the right to know who is paying [for ads]."

Even if the measure to block the FCC from funding the political ad rule passes the House, it still has to get through the Democrat-controlled Senate and be signed by President Obama, whose administration has supported the transparency rule.

A spokesperson for Emerson did not respond to a request for comment. At a hearing in March, Emerson grilled FCC Chairman Julius Genachowski about the then-proposal.

"Why do you care about this?" the congresswoman asked Genachowski. "You have plenty of other things that are far more important to deal with since we already have a Federal Election Commission who has jurisdiction over campaign finance. ... Why in the world is this a big priority?"

At the hearing Wednesday, Rep. Hal Rogers, R-Ky., the chairman of the Appropriations Committee, joined other Republicans in arguing that the new rule would be overly burdensome for stations.

Since 2010, the National Association of Broadcasters Political Action Committee has donated $7,000 to Emerson's campaigns. Emerson's home state of Missouri is expected to be a swing state in 2012, meaning it will see a huge infusion of political ad spending.

Both the broadcasters association and the FCC declined to comment on the new appropriations language.