Advertising watchdogs are to investigate the validity of claims made in a campaign promoting British pork.
The move follows a complaint by animal welfare charity Compassion in World Farming to the Advertising Standards Authority.
The complaint centres on an Assured Food Standards “Pork not Porkies” campaign promoting pig meat stamped with the Red Tractor logo.
Compassion in World Farming said it objected to claims that pork stamped with a Red Tractor logo, is high welfare pork.
Joyce D’Silva, the charity’s director of public affairs, said: “We are very surprised by this claim from the Assured Food Standards.
“Many consumers look to labels such as The Red Tractor and trust that they are buying products from animals that have been treated well and raised humanely.
“However, Red Tractor standards are so minimal that it cannot claim that all its pork products are high welfare. It is unfair to mislead consumers in this way.”
Some pigs reared under the Red Tractor scheme would be in higher welfare outdoor, free range systems, said Ms D’Silva.
But many others would inevitably be kept in crowded pens possibly without straw or other enrichment material, she claimed.
They would be unable to carry out key natural behaviours and many will have their tails trimmed, or docked.
“Compassion believes it is unfair for farmers who rear their pigs to a genuinely high standard to be labelled with the same stamp.”
The charity was also concerned about Red Tractor guidelines on the use of slatted flooring and farrowing crates for new mother pigs.
Red Tractor guidelines allow the use of farrowing crates and the provision of bedding material for farrowing pigs is optional.
Ms D’Silva said Red Tractor standards did not represent “high welfare” but were in fact conditions of very considerable deprivation.
The full letter from Compassion in World Farming to the ASA can be downloaded here.
Assured Food Standards is expected to respond to the claims later.
Posters promoting “Pork not Porkies” were among two adverts displayed at almost 2,000 sites around the country between 3 and 16 October.
The aim was to make shoppers think about the pork they are buying and encourage them to look for the Red Tractor Pork logo.
Consumers were also encouraged to visit the lovepork.co.uk website or Facebook page to make the Pork Promise.
So far, more than 1300 shoppers have signed up.