The Federation of Small Businesses (FSB) has complained about a recent advert from HM Revenue & Customs.
The Revenue said the majority of business owners are honest
It has asked the Advertising Standards Authority (ASA) to take action over the advert which was published in national newspapers on 14 December 2005.
Using an image of a plumber hiding under a sink, the advert encouraged people to report self-employed workers who do not pay their taxes.
The FSB claimed the advert was "harmful and misleading".
Revenue & Customs apologised if the intention behind the advert had been misinterpreted.
FSB spokesman Simon Sweetman complained that the advert "tars all of the UK's 2.72 million self-employed people with the same brush".
"The vast majority of self-employed people abide by the law and pay their taxes," he said.
"The self-employed in the UK contribute to the economic well-being of this country and this advert is a harmful and misleading attack upon them."
But a Revenue & Customs spokesman said the advert had been aimed at a minority of non-tax payers.
"We are well aware that the majority of small businesses are entirely honest and scrupulous in their dealings with us," the spokesman said.
"We are not in any way suggesting that all or even most small businesses fall into this category," he added.
The ASA said it was looking at the complaint and would decide next week if there was a case to answer.
In recent years the ASA has investigated three complaints about Inland Revenue adverts, two of which have been at least partly upheld.
In June 2005 the ASA partly agreed with a complaint about an advert for Child Trust Funds, ruling that it should have mentioned that the value of an investment account could go down as well as up.
Five years earlier, in June 2000, the ASA ruled that another leaflet, advertising the Working Family Tax Credit, was misleading and confusing.
It had failed to make clear how many hours someone should work to qualify as a full-time worker for the purpose of claiming the credit.