CIWF described this emergency procedure, as involving the sealing of all apertures on poultry sheds followed by shutting down the ventilation system and leaving the chickens to die slowly through loss of oxygen, overheating as well as effects of the disease.
The CIWF has mentioned that the Department for Environment, Food and Rural Affairs (Defra) had said that this method of culling would be used only as a last resort.
However CIWF claimed this method of extermination appeared to breach internationally agreed guidelines through failure of ensuring that induction of unconsciousness is immediate thereby failing to avoid anxiety, pain, distress and suffering.
Philip Lymbery, CIWF chief executive has said, 'It is possible that many birds will die in shocking circumstances and we could be faced with scenes in which piles of dead birds culled in this fashion, become a common sight - comparable to the shocking scenes at the height of the foot and mouth disease crisis.'
'We believe that this method is potentially so inhumane that it should not be used even as a last resort.'