The National Association of Broadcasters came out swinging in an emergency motion today at the U.S. Court of Appeals in Washington. The trade group wants the court to stay an FCC ruling that requires stations to put on the Web information about political ad sales that they already must make public on paper. The NAB says that TV stations will be “at a distinct disadvantage to their non-broadcast competitors” if they have to post the ad rates online after a sale. It would especially help cable and satellite providers — who aren’t subject to the FCC rule — to adjust ad prices to win business from broadcasters. Indeed, the filing says, the damage to stations’ ad sales efforts would be so great that it “outweighs the benefits” to people who want to know who’s spending how much on TV to influence their opinions in an election. In April, the FCC adopted its new rules requiring the top four stations in the 50 largest markets to send their political ad data to the regulators for online posting. The rules were published last week in the Federal Register, putting them on track to take effect in early August. FCC chairman Julius Genachowski said at the NAB’s annual confab in April that opposing the online disclosure plan is “against technology, against transparency and against journalism.” Public interest and free speech groups have also endorsed the FCC’s new rules.