Even if it did, the idea could not work commercially, because the overwhelming majori-ty of British pig farmers, refuse to contemplate feeding swill, because of the disease risk involved and because they are opposed to cannibalistic feeding on ethical and food safety grounds.

The National Pig Association (NPA) is opposed to feeding swill because even if the practice were to be allowed by law, inevitably there would, sooner or later, be a regulatory breakdown in one or more of the European Union’s 28 member countries, with the consequent serious disease risk.

The British pig industry already uses 1.23m tonnes a year of co-product from the hu-man food chain and this accounts for 43.9 per cent of total pig feed produced.

"Pig producers prefer to describe 'waste food' as 'co-product' because, in the pig in-dustry’s view, no food is waste if it can be used safely in nutritious pig diets," said NPA chairman Richard Longthorp.

"But any waste food we use must be clean, wholesome, contain zero porcine material and must have an independently-audited supply chain that is strictly controlled and regulated. Pig farmers stand ready to do everything they can to recycle waste food — but that does not mean they are prepared to let their animals become society’s dust-bins."

Notifiable diseases such as foot-and-mouth disease, classical swine fever and African swine fever can survive in meat for long periods and are easily transferred from meat to other produce, which is why feeding some waste foods to pigs is so problematic. These diseases are easily transferred between pigs and some can infect other livestock species too, so they can spread quickly.

Given the prevalence around the world of foot-and-mouth disease, classical swine fever and African swine fever, and the free movement of people, vehicles and goods, some of these diseases are inevitably already present in Britain and the only way to prevent economically-debilitating national outbreaks is to prevent the viruses coming into contact with farm animals.

Feeding untreated waste food to pigs has been directly responsible for major notifiable disease outbreaks around the world, including the 2001 foot-and-mouth outbreak in Britain. The current African swine fever outbreak in Russia continues to spread, as a result of illegal movements and feeding of infected waste food to pigs. The disease remains out of control and there is a risk it could spread to the European Union.