State Fair officials are asking the Michele Bachmann for Congress campaign to stop using its logo in a television ad that began running Monday.

Says Fair spokeswoman Brienna Schuette in an e-mail: "The Minnesota State Fair logo is trademarked. Michele Bachmann’s campaign did not ask for permission to use the logo. Michele Bachmann’s office is being contacted to end the unauthorized usage of the Minnesota State Fair logo. The State Fair does not endorse any candidate running for political office."

Media can often use corporate logos or trademarks in stories under the “fair use” doctrine, said John Borger, a Minneapolis media lawyer with Faegre & Benson. (And there's no pun intended, in this case, with “Fair doctrine.”

But Borger, whose firm also handles First Amendment issues for MinnPost, said in this campaign ad case, fair use may not apply, explaining:

“ 'Fair use' does not allow a speaker to use someone else’s trademark in a way that falsely suggests that the trademark owner sponsors or endorses the speaker’s activities or positions. The statement of the State Fair makes clear that the Fair does not endorse Rep. Bachmann’s advertisement or any other political advertisement, so if some viewers reasonably might understand logo’s appearance in the advertisement as an endorsement by the Fair, that suggestion in the advertisement would be false and an unfair use of the trademark.”

The ad criticizes challenger Tarryl Clark for votes on taxes and flashes the fair logo when the spokesmodel says: "I know, I know, it's State Fair time and you don't want to hear about politics."

The logo appears again when he says: "While you're at the Fair, just ask her: '"What's up with voting to tax my beer?'"

A press spokesman for Bachmann was not available when we called for a comment, but we'll update this story as needed.