U.S. District Judge Charles Breyer will uphold the bulk of a San Francisco ordinance requiring political ads to disclose top donors and secondary funding sources.

Proposition F requires print, audio, and video political ads disclose the top three donors who contributed at least $5,000. If one of those donors is a PAC, the committee’s top two donors must also be disclosed.

The judge rejected claims the ad disclosure law hinders political speech.

Yes on Prop B argued the law unconstitutionally burdens its right to free speech and cited an en banc Ninth Circuit panel decision in American Beverage Association v. San Francisco blocking the city from requiring health warnings taking up 20% of billboard ads for sodas and sweetened drinks.

Judge Breyer found the court decision was not really on point because Proposition F was passed by a voter referendum and regulates political speech as opposed to commercial speech.

The judge also rejected an argument donor information is easily accessible on the San Francisco Ethics Commission website stating putting the onus on voters to look up the information would not match the law’s intent.

While refusing to block most of the law, Judge Breyer agreed requiring lengthy disclaimers for small print and short length political ads is likely unconstitutional and indicated he will issue a partial injunction blocking those types of restrictions.