About 120,000 pigs could be culled and their carcasses dumped because of a shortage of butchers, the industry has warned.
A workforce shortfall has meant farms are running out of space to keep the animals that should already have gone for meat, raising welfare concerns.
While the sector had previously warned of the problems faced, it said the situation was now becoming critical and again pressed the government to relax the visa rules to fill the labour gap.
An acute shortage of butchers and slaughterers in the meat processing industry has been exacerbated by COVID-19 and the UK’s post-Brexit immigration rules, which has restricted the flow of east European workers.
The government has already announced a plan to issue temporary visas for 5,000 foreign lorry drivers and 5,500 poultry workers to ease shortages, but has given no indication it will introduce schemes for other areas.
Ministers argue businesses should invest in their workforce and improve pay and conditions.
Lizzie Wilson, policy services officer at the National Pig Association (NPA), said the shortage of butchers meant processors were operating at 25% reduced capacity.
As a result, mature pigs ready for processing are backing-up on farms.
She said: “There’s about 120,000 pigs sat on farm currently that should have already been slaughtered, butchered, be within the food chain and eaten by now.
“It is getting to the point where we are saying to government if we don’t get some help soon we’re going to have to look at culling pigs on farm, because that’s our only option now.”
Ms Wilson said customers were already seeing the impact of the crisis on supermarket shelves as processors had reduced pork product ranges.
The association has also urged the country’s retailers to continue buying homegrown pork and not cheaper EU products, warning that many producers would go bust if they were not properly supported.
David Lindars, technical operations director at the British Meat Processors Association, said a cull “was getting very close”.
“I don’t understand this government any more. It has to get to white shelves in the supermarket scenario before they believe it,” he said.
A government spokesperson said it was aware of the challenges the pig industry had faced in recent months.
“We are keeping the market under close review and continuing to work closely with the sector to explore options to address the pressures the industry is currently facing,” they said.