A group of high-profile restaurants will today prepare a free public feast as part of a campaign to encourage the EU to lift its ban on feeding catering waste to pigs.
The pork feast for more than 5,000 people in London's Trafalgar Square at lunchtime aims to raise awareness of The Pig Idea campaign, which is calling for legally-allowed food that is unfit for humans to be used as pig feed.
Campaigners say the move would conserve food supplies, cut waste and farming costs and protect the environment.
They also want a change to European law to allow food leftovers to be fed to pigs, backed by the introduction of a robust legal framework for its safe processing and use to avoid spreading animal diseases.
Using waste from catering and homes as pig "swill" was banned in the UK in 2001 in the wake of the foot and mouth crisis due to concerns the disease originated on a farm illegally feeding pigs unprocessed restaurant waste.
The ban was then extended across Europe.
The "pig bins" that were once a familiar sight in schools and canteens vanished, and pig farmers increased their use of crops that people could otherwise eat, such as wheat, soy and maize, as animal feed.
But the campaign, led by chef Thomasina Miers and food waste expert from Feeding The 5,000 campaign Tristram Stuart, says feeding food waste to pigs would reduce the costs of disposing of leftover food and the price farmers have to pay for animal feed.
It would protect important habitats such as tropical rainforest, which is under threat of clearance to provide more land to grow animal feed crops, and cut environmental impacts such as the greenhouse gases rotting food produces.
Crops such as cereals could be diverted away from feeding pigs to humans, improving food security, and jobs and revenue could be created in a new "eco-feed" industry for collecting, treating and distributing the waste so it could be fed to pigs.
The pair have been rearing eight pigs, which will form part of tomorrow's feast, at Stepney City Farm in east London, on a menu of food waste from around the capital.
Restaurants such as Wahaca, Bistrot Bruno Loubet, Cabana, The Delaunay, Paternoster Chop House, Le Pont de la Tour and Soho House will offer up dishes ranging from braised pigs' cheeks to pork belly pizza.
The campaign aims to restore public confidence in the practice of feeding surplus food to pigs and raise awareness among supermarkets, food businesses, officials and pig farmers about using already legally-permissible food waste, as well as lobbying to change the law.
The bid to return to the traditional practice of feeding surplus waste food to pigs reared for meat is supported by high profile "ham-bassadors" including celebrity chefs Hugh Fearnley-Whittingstall and John Torode.
Mr Stuart said: "Feeding food waste to pigs is a millennia-old tradition and a fantastic way of producing meat that avoids the colossal environmental cost of growing commercial pig feed, much of which is currently imported from South America where it is causing deforestation and the destruction of the Cerrado habitat.
"Farmers could save money by using local sources of food waste instead of buying pig feed, which is getting ever more expensive with the squeeze on global food supplies. This would also liberate crops currently fed to livestock that could instead be used to feed people.
"We've got to make our food system more sustainable and less vulnerable, and rearing pigs on food waste - alongside eating less meat overall - is one win-win way of achieving this."
A number of other countries including Japan and South Korea allow recycling of properly treated food waste into livestock feed, with waste heated to kill pathogens such as foot and mouth.
A Defra spokeswoman said: "Feeding farm animals catering waste, kitchen scraps or meat is prohibited to prevent introduction and spread of diseases, such as foot and mouth, swine fever and avian flu."
The British Pig Executive (Bpex) said it welcomed any initiative to reduce food waste but had concerns with swill feeding and The Pig Idea's campaign to reintroduce it.
It said the process of swill feeding was "a lot more complex than what is currently being portrayed" and required a set of strict controls, with standards that were difficult to maintain.
Bpex board member and free range pig farmer Alastair Butler said: "In 2001, swill feeding cost this country £8 billion, it saw 6.5 million animals slaughtered and 10,000 farms had their livestock culled.
"For these reasons, we believe the risk of swill feeding is just too great. The majority of pig farmers are against the reintroduction of swill feeding because of the very real risk it presents to their animals and livelihood."