The Federation of Small Businesses (FSB) has hit out at a government advertisement which it says unfairly implies that the self-employed are tax dodgers.

The HM Revenue & Customs (HMRC) advert, which has appeared in the national press, feature a plumber hiding under a kitchen sink.

Aimed at encouraging people to report small business owners who avoid paying their legal contributions, the accompanying text says: "With your help, we'll make sure self employed people who don’t pay their tax have nowhere to hide".

But Simon Sweetman, FSB tax spokesman, complained that rather than representing a worthy campaign, the advert is offensive to entrepreneurs running their own business, the majority of whom are law abiding.

"We are disappointed that a campaign that could have gained widespread support has instead resorted to a clumsy advert that tars all of the UK’s 2.72 million self-employed people with the same brush," he said.

"The vast majority of self-employed people abide by the law and pay their taxes.

"We find it particularly offensive that the implication in the advert is that all self-employed people do not pay their taxes. 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."

The FSB has made a formal complaint to the Advertising Standards Authority.