Surplus pigs may need to be shot on East Anglian farms within days unless a dire shortage of carbon dioxide (CO2) at slaughterhouses is resolved, warned industry leaders.
The gas is an essential part of the slaughter process for most pigs and chickens, as well as being used to refrigerate and extend the shelf-life of other meat products.
Most of the UK's food-grade CO2 is produced as a by-product of fertiliser manufacture at two large plants in Teesside and Cheshire which closed last week due to a sharp rise in natural gas prices.
The resulting lack of supply has prompted concerns over imminent meat shortages in the shops, and of a "breaking point" for East Anglia's turkey suppliers in the run-up to Christmas.
And there are also major worries for the region's pig farms, already battling a backlog of thousands of animals due to a post-Brexit shortage of workers in meat processing plants.
Norfolk pig farmer Rob Mutimer, of Swannington Farm to Fork near Reepham, is also chairman of the National Pig Association.
He warned that if the situation does not change, farmers could be forced to humanely slaughter their own animals - possibly as early as next week - due to a lack of space and feed.
"To be hit with this now when we were already in such a perilous position - the consequences are unthinkable," he said.
"We have got abattoirs and processing plants that could run out of CO2 by the end of the week.
"If the factories stop slaughtering next week we will end up shooting these animals on farm or sending them away to be rendered, to dispose of carcasses like what happened during foot and mouth disease.
"If we don't get any CO2 there will be people next week calling for a cull of pigs because they wont be able to keep them. It is a terrible situation to be in.
"Nationally we believe we have up to 100,000 pigs on farms that shouldn't be there, and I have got pigs which are 20kg heavier than they should be.
"Our contingency plans are full. We cannot keep these animals for weeks and weeks."
Brexit-impact-on-fruit-pickers
Pigs are a vital part of the region's agricultural economy, with an estimated 20pc of the national herd kept in Norfolk and Suffolk.
Mr Mutimer said farmers were already struggling after losing as much as 20pc of their contract values due to the existing workforce problems in the food chain - but he fears many will go out of business if that figure rises to 70pc to 80pc as a result of the CO2 crisis.
"We have lost 22,000 sows from the [UK's] herd in the last six months, and I think that is the tip of the iceberg," he said.
The British Meat Processors Association (BMPA) says manufacturers have reported they have between five and 15 days' CO2 supply left, meaning some companies could be forced to close production lines and stop receiving animals.
BMPA chief executive Nick Allen said: "That will cause farmers huge animal welfare problems and British pork and poultry will stay off the shelves. We're two weeks away from seeing some real impact on the shelves."
Other companies producing beef and lamb, which use different methods of stunning prior to slaughter, could continue producing retail packs of meat, but without CO2 used in the vacuum packing process, up to five days shelf life would be lost, said the BMPA.
"We're hoping and praying the government can negotiate with these [fertiliser] plants to reopen," added Mr Allen. "But even then, it'll take about three days to restart."
A government spokesperson said: “We are monitoring this situation closely and are in regular contact with the food and farming organisations and industry, to help them manage the current situation.
“The UK benefits from having access to highly diverse sources of gas supply to ensure households, businesses and heavy industry get the energy they need at a fair price."
The firm operating the two closed fertiliser plants, CF Industries, says it does not have an estimate for when production will resume.
The National Farmers' Union says it is seeking "urgent clarification" from CF over the closures, which have also prompted "immense concern" among arable farmers over the availability of ammonia nitrate fertilisers.
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