Supplies of festive food staples including pigs in blankets, glazed hams and three-bird roasts could be hit by Brexit-related labour shortages in the meat industry.

Some specialist processing plants that require additional seasonal labour for hand-finished products are already struggling to meet orders, according to the National Pig Association (NPA), which represents processors, abattoirs and farmers.

Most meat processing plants have labour shortages equivalent to up to 15% of their required workforces, as the fall in the value of the pound since the 2016 referendum has combined with uncertainty about residential status, according to the Grocer trade journal. But the labour shortage at seasonal specialists could be as much as 30% because they usually increase their workforce by up to 15% at this time of year, says the British Meat Processors Association.

Ed Barker, senior policy advisor of the NPA, said several processors who relied on regular semi-skilled labourers from Europe had said they were struggling to fulfil orders ahead of Christmas.

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“It was difficult last year and the year before but it seems to be particularly squeezed this year. Three years of uncertainty and the fall in the sterling to euro exchange rate has changed the mind of a lot of labourers who have decided to bite the bullet and go back home.”

The British Poultry Council said its members were about 20% short of regular staff and that seasonal specialists, such as turkey and goose producers, were now under pressure because of difficulties in hiring up to 2,000 extra workers usually required ahead of Christmas.

The concerns about meat production come after it emerged that thousands of tonnes of fruit and vegetables are being left to rot in UK fields because of a shortage of pickers and packers in the face of continuing Brexit uncertainty. Last month some fruit farmers said they had 30% fewer workers than required.