Pig farming leaders have demanded urgent action from ministers to deal with a backlog of animals which is worsening - despite a government rescue package.

The National Pig Association (NPA) and National Farmers' Union (NFU) have joined forces to call on environment secretary George Eustice to convene a "supply chain summit" to address the crisis.

Post-Brexit labour shortages in meat processing plants, complicated by Covid absences, have created a backlog of pigs on UK farms, now estimated at more than 200,000.

In a joint letter, NPA chairman Rob Mutimer and NFU president Minette Batters also demanded improvements to an industry support package which they say has delivered minimal benefit to pig producers so far.

Defra introduced measures in October including temporary six-month visas for up to 800 pork butchers - who it says began arriving in December and will continue to arrive throughout January and February.

But the NPA says it is aware of only 105 butchers that have, or are due to, arrive under the temporary visa scheme, and there has been little or no take up of the Private Storage Aid and Slaughter Incentive Payment Schemes.

Mr Mutimer, who is a Norfolk pig farmer, said: "We need Defra to design measures that will actually appeal to the processors, so they can process more pigs and get these contract pigs off the market.

"Christmas is always difficult and we thought that once we got that out of the way things would get better. But actually they got worse, because of Omicron.

"The mental stress of this has been growing for 12 months now, it is just horrendous.

"It is all very well saying it will be better soon, but we need it under control, because it is totally out of control at the moment."

A Defra spokesperson said: “Following our package of support measures, we expect progress to be made on reducing the backlog of pigs on farms in the coming months.

“We continue to work closely with all parts of the sector, and have extended the Private Storage Aid scheme until March 31, and launched a new Slaughter Incentive Payment earlier this month which increases the payment rate to £10 per pig.”

The NPA says it has received reports of more than 35,000 healthy pigs being culled as a result of the backlog since September - although it warns the actual figure will be much higher.