MOST UK supermarkets and high street food chains are still sourcing their pork almost entirely from factory farms, it has been claimed.

Animal welfare group Farms Not Factories this week released a survey of pigmeat sourcing practice across a broad range of UK retailers, and highlighted that nearly three-quarters (73%) of mainstream outlets bought from intensive systems that placed pigs in 'permanent indoor confinement in barren, overcrowded pens'.

Looking across the range of welfare labels affixed to the pigmeat for sale in the UK, the campaigners endorsed the top end of free-range, RSPCA and organic assurance marques, but 'drew the line' above the Red Tractor standard, which they condemned as too low to offer meaningful welfare benefits for the animals.

Farms Not Factories has written to the CEOs of the high street chains involved to demand a change in their buying policy, and has also called on the UK government to ban the importation of pork produced in conditions that would be illegal in the UK.

Fronting this new campaign is Game of Thrones actor Jerome Flynn, who took part in a stunt on London's Oxford Street, kneeling caged in the middle of the road, to highlight the welfare objection to the use of confined space meat production.

“Factory Farming is one of the most horrific examples of how far we have strayed from our hearts in the relentless drive for profit and so called progress," said Mr Flynn. "We call on all our major retailers to do the right thing and lead the way by ceasing to trade in any meat that isn’t high welfare. If we are going to farm and take the lives of our animals, then it is our responsibility to honour and care deeply for their lives while they are here, by giving them space to play and roam happily. I call on anyone with a compassionate heart to send a strong message to our government and our supermarkets by refusing to buy any factory farmed meat! It’s a horror story that has to stop!”

Campaign director Tracy Worcester personally bought single shares in a number of food chains so that she could attend shareholder meetings and ask questions of their management directly – and has now warned that companies' share values will fall if they don’t follow consumer trends away from factory farmed meat, given that many shoppers would boycott businesses with poor animal welfare standards, were they aware of them.

Ms Worcester said: "As consumers we can all help end the horrors of factory farming, that causes endemic animal suffering by cramming pigs into barren concrete cages, spreads excessive slurry and nitrates destroying ecosystems and undercutting smaller scale family farms – only buy RSPCA Assured, free range or best of all organic."