The ad shows the New England Patriots' Moss -- then with the Minnesota Vikings -- celebrating in the end zone after a 2005 touchdown by pretending to moon Packers fans at Lambeau Field, an act long resented by Feingold's Wisconsin constituents, the Washington publication Politico reported.
The campaign ad also shows other touchdown celebrations from NFL games coupled with a message that Republicans are celebrating expected 2010 election gains prematurely.
But the NFL objected to the use of the images, and Feingold said Tuesday he has agreed to take them out of the ads.
"We are happy to remove it if they don't like it," Feingold told Politico in Oshkosh, Wis., where he was campaigning against GOP opponent Ron Johnson. "There's plenty of other examples of dancing in the end zone, the worst one being Mr. Johnson and the corporate interests that think they're going to win everything in this election."
"Sen. Feingold's mask is off," responded Johnson spokeswoman Sara Sendek. "He ... is using the NFL licensed footage without permission in his latest attack ad."