According to The Independent, pork farmers have been conducting a high-profile advertising campaign to encourage consumers to buy more expensive British produce, claiming that standards are higher than they are on the Continent. But the images, taken at farms linked to leaders of the industry, raise serious concerns about the welfare of the majority of the country's 8 million pigs.

Vets at the Government's Animal Health agency, which enforces welfare legislation and conducts regular inspections of farm premises, said it would investigate the findings.

An advertising campaign run by BPEX and the National Pig Association last year, "Pigs Are Worth It", showed pictures of clean pigs standing outside on straw and boasted shoppers were getting "a top quality product from a well cared for animal". Animal welfare campaigners have asked the Advertising Standards Authority to ban the adverts, saying they mislead the public about the conditions experienced by the two thirds of the UK's pigs that are reared indoors.

Animal Aid claimed its investigation showed that farmers were "falling considerably short" of the images it portrayed in its campaigning. Shot in Cornwall, Somerset, Lincolnshire, North and East Yorkshire, the footage shows pigs with sores where they have rubbed against metal bars; farrowing crates that prevent sows from moving; pigs with bite marks; collapsed and convulsing animals; pigs covered in excrement; dirty pens; and routine tail-docking.

Two farmers, singled out by Animal Aid because they sit on BPEX, denied conditions at their farms were poor. Meryl Ward, a director of Ermine Farms, which runs Sandhouse Farm at Appleby, Lincolnshire, said the faeces had been in "dunging area". "Those are not pigs left head to toe in excrement," said Mrs Ward, who serves on the Government's Farm Animal Welfare Council. "This group uses emotive language to make something sound terrible when we think it works very well and we are very proud of it."

John Rowbottom, a member of the National Pig Association Producer Group, acknowledged that shoulder sores on the sows at Norway Farm in Bridlington, East Yorkshire, were a "genuine concern" but dismissed other complaints, including bite marks from bullying. "There's nothing up there that would concern me, except the sore shoulders," he said.

Peter Stevenson, chief policy officer for Compassion in World Farming, said the British pig industry's claim to high welfare standards was not true. "When you look at the way most of these young pigs are reared it's absolutely classic factory-farming," he said. "Pigs are just as lively and curious as any other young animal... so to keep them in utterly barren conditions is immensely harmful to their welfare. I think most of the public would be shocked to see pigs reared in these conditions."

View The Independent story by clicking here.