The Public Fundraising Regulatory Association has accused two Conservative councils in London of orchestrating a campaign against face-to-face fundraising.
Wandsworth published a press release bemoaning "the legions of chuggers who are swarming around Tooting Broadway pestering passers-by for their bank details".
Councillor James Cousins, the council's regeneration and community safety spokesman, said: "Some traders near the station have told us that their takings have gone down dramatically since the chuggers arrived.
"We have tried to engage with the PFRA and asked it to remove Tooting Broadway from its list of approved pitches but the response we have had back has been unsatisfactory."
On the same day, Westminster City Council published figures saying more than 500 face-to-face fundraisers had worked on four busy London streets in six weeks. Councillor Daniel Astaire said: "Businesses are extremely irritated, with potential customers crossing the road because they don't want to run the gauntlet of chuggers."
The PFRA issued a response saying it has been trying to set up a meeting with Wandsworth to establish a site management agreement for the past month. The agreement would determine the amount of street fundraising in the borough, it said.
The PFRA has an informal site management agreement with Westminster and claimed "no issues or problems were reported to us" before yesterday.
Mick Aldridge, chief executive of the PFRA, said he suspected the two Tory-run councils were orchestrating a campaign against street fundraising.
"I suspect that formally or informally Westminster and Wandsworth have been conferring," he said. A spokeswoman for Westminster denied this.
Aldridge said neither council had established any firm evidence of public concern about street fundraisers and that Westminster City Council's figures were equivalent to four face-to-face fundraisers a day on Oxford Street. "You would have trouble finding four on Oxford Street," he said.