More than 90 per cent of pigs are confined indoors in barren pens after being weaned and many have no chance to forage

Supermarkets are selling meat with misleading labels that falsely suggest that the animals were reared outdoors when they actually spent their lives inside giant sheds on factory farms.

Millions of pigs and chickens from intensive indoor farming systems are slaughtered each week to supply British consumers with cheap meat.

Retailers conceal how the animals have been reared by using images on the labels of idyllic country scenes with animals roaming free.

Gammon and chicken sold by Asda comes in packs showing pigs and chickens on green hillsides. The animals used in the packs were reared indoors.

Packs of chicken sold by Tesco carry images of birds on grass, something they would not have come across in their sheds.

Bernard Matthews, one of the biggest producers