Two House Democratic leaders who've gone on record as supporting a performance royalty on radio stations are asking FCC chair Julius Genachowski to "investigate allegations of retaliation" by broadcasters.

Last month the Music First Coalition filed a 17-page request asking the FCC to investigate several tactics broadcasters have allegedly used to block the fee. Among its claims is stations boycotted 13 artists who have been most active in the fight. The group also claims a radio programmer in Florida warned a label rep their artists' support of a royalty would have a "chilling effect" on the relationship with his station.

No broadcaster has accepted commercials promoting the royalty. Representatives Henry Waxman (D-CA) and Rick Boucher (D-VA) aren't picking sides but tell the new FCC chairman that if the agency's initial review shows there's credence to the allegations, the FCC should conduct a "more thorough examination" of the claims. The NAB has labeled Music First's call for an investigation "desperate" and a "stunt."