A Northampton Town supporter is leading a campaign to force football clubs to ban payday loan firms from advertising on their websites.
Bob Ward, a 67-year-old lifelong fan, said: "We would prefer clubs to seek other advertising revenue than earning money from the dubious activities of payday lenders."
His anger was raised by seeing an ad for Wonga on his own club's website through a deal with the Football League.
Research among fellow fans quickly revealed that many club websites are prime advertising locations for expensive payday loan firms. He quickly got support for his campaign from 24 clubs, including Burnley and Southend United.
They want clubs to help fans rather than offer them expensive credit. "If clubs really wish to advertise short-term loans, it would be better to give publicity to credit unions," Mr Ward said. Fans should email clubs urging them to opt out of the Football League Interactive's Wonga ads "until there is proper regulation of the industry and a cap on the interest rates that can be charged", he added.