RISQUE billboards across Barnet promoting longer lasting sex are perverting the minds of youngsters, according to a councillor.

The signs, which state "Making love? Do it... longer!", are part of an ad campaign run by the Advanced Medical Institute (AMI) promoting treatments for Erectile Dysfunction and premature ejaculation.

Councillor Brian Gordon, assistant cabinet member for policy and performance, was so incensed by the advertisements, he launched a formal complaint with the Advertising Standards Authority (ASA).

It is not the first time the AMI has been critised for distasteful advertising. Last year the company sparked hundreds of furious letters to the ASA when it emblazoned the phrase "Want longer lasting sex?" on giant orange posters across the capital.

Mr Gordon said he had received "a number of" complaints about the posters, which can be found near Five Ways Corner in Watford Way, Mill Hill, and along the Colindale section of the Edgware Road.

The councillor added: "I realise there is a degree of freedom of speech in this matters, but there needs to be limitations on that, hopefully by consent rather than law.

"There should be an understanding that certain things are indecent. This poster, talking about longer lasting sex in such a prominent way, vulgarises and cheapens something that should be seen as sacred.

"There is no question that such a poster can pervert the minds of many right-thinking people, including particular children, who are very impressionable."

Father-of-six Lawrence Littlestone, 61, from St Margaret's Road, Edgware, also filed a formal complaint because he was offended by the prominence of the posters.

He said: "I don't find the content offensive in itself, but I do find the siting of it offensive.

"There are five primary schools in this neighbourhood and children are being carried to and from school along the A5 every day. They will see it and start asking questions.

"I know, as I am a parent and my nine-year-old asked me what it was all about, and I had to come up with some glib response.

"I don't object to such an advert in an adult magazine or a newspaper, where children wouldn't see it, but I find it quite offensive that it is so in your face."

The ASA is considering the complaint before deciding whether to take further action.