The president of the British Veterinary Association said: 'Our view is that all animals should be stunned before slaughter, based on peer reviewed evidence that indicates an unacceptable time lapse between slaughter and the onset of permanent insensibility when animals are not stunned.

Animals must also be stunned before slaughter under EU regulations.

However Britain allows an exemption for those who oppose because of religious beliefs and the number of animals killed without stunning appears to be on the rise.

The Halal Food Authority, which polices slaughter methods, says stunning can only be used if the animal survives and is then killed under halal ritual. But some Islamic groups do not allow any form of stunning before slaughter.

Any meat offered for human consumption where the annimal has not been stunned prior to slaughter should be clearly labelled as such in my view.