The Government has warned carmakers to tone down their ads or face the prospect of legally enforceable sanctions if they put too much emphasis on speed and performance.
Now the Advertising Association is to tell agencies and their car clients not to risk provoking ministers by being seen to encourage irresponsible driving.
The Department for the Environment, Transport and the Regions is demanding that all car manufacturers should toe the safety line - even if their models are not aimed at the 'boy racers' who are the main targets of the DETR's road safety message.
But industry bodies are sceptical of DETR-commissioned research on the links between advertising and bad driving and claim that any clampdown will not help the Government achieve its objective of a 40 per cent cut in road deaths and serious injuries by 2010.
'We'll do all that's necessary to show we're responsible but we're highly dubious about the DETR's research,' Sara Price, the AA's head of public affairs, said.
'We will be asking agencies and their clients to bear in mind what the DETR is saying, but it's difficult to see how statutory controls would lead to a higher level of compliance.'
DETR officials revealed details of the research, which they hope to publish before Christmas, to representatives of the AA and the Independent Television Commission at a meeting last week.
The DETR's head of publicity, Tony Allsworth, said: 'I don't think car ads will change people's behaviour but they can contradict the messages we are putting out. Agencies and car manufacturers have not been concerning themselves with the effects that their ads are having on those outside their target audiences.'
Failure by carmakers to be more responsible could result in the Government renewing its pressure on the European Union for a statutory code of practice for car advertising.
'That's a matter for ministers and I don't want to threaten advertisers,' Allsworth added. 'A statutory code would be a last resort and we've not reached that stage yet.'