"We had 24 hours of real angst until further tests showed it was a false alarm," said Stewart Houston, a member of Defra's Animal Health and Welfare Board. "For a while it really did look as if the disease had arrived."

His report concentrated minds at NPA's recent Producer Group meeting, with members speaking out against any relaxation of current feed safety rules.

"Can I just remind everybody," said Marcus Bates, of the British Pig Association, which looks after the interests of pedigree pig-keepers, "that Bobby Waugh was not a hobby farmer?"

He warned that illegal swill feeding was still happening, with waste food being supplied by the lower end of the restaurant trade.

"But this is not the smallholder sector we are talking about. Most smallholders are educated people who know the risks and know it just isn't worth it. And they don't want swill feeding to come back in any shape or form — ever.

"As far as they are concerned it is part of the dim and distant past and they don't want to be involved with it."

NPA general manager Zoe Davies said retailers were trying to reduce food waste and the campaign by the "Pig Idea" to bring back swill-feeding might appear initially attractive.

"So every time we meet with retailers we brief them on the subject and make sure they know the risks, and they see our point."

She said that far as she could ascertain, retailers had reached the stage of feeding direct-from-store bakery waste into the cattle sector. "They can do this directly from their stores as long as they have an approved HACCP plan agreed with their local Animal Health office.

"In my view there is still a risk and I wouldn't want to see that product going into pigs, but it is something they can do legally."

Andrew Freemantle said the idea of treatment plants for swill was probably flawed and might not be any better than importing soya — which in any case was something that producers were keen to reduce.

Zoe Davies pointed out that most pig farmers were not set up for liquid feeding so the treated swill would need to be dried "and that would have an enormous impact on the amount of energy required, regardless of other issues such as variability and protein quality."

She added, "The thing that really frustrates me is that this is being sold as an idea that pig farmers support, and by and large they don't."

Mr Bates reported that at a recent British Pig Association meeting everyone present was horrified that the impression was being given that pig-keepers supported a return to swill feeding.

"What worries me is that this is the first time that there is a moral imperative on us to feed swill. The thing that struck me about the recent Newsnight programme on the subject was Kirsty Wark talking about how pig-keepers could save the Amazon.

"That is where it is quite different from any challenge we have faced before and that's why I think some sort of rebuttal based on energy efficiency along with all the other problems would be very helpful."

Producer Sally Stockings noted that memories must be very short if people had forgotten already about the pyres that were burning across England in the 2001 foot-and-mouth outbreak.