Slaughter without stunning unnecessarily compromises the welfare of animals at the time of death, however almost a quarter (24.4 per cent) of sheep and goats slaughtered between April and June this year had their throats cut without first being made insensible to pain.

An increase from 15 per cent in 2013, when the EU and UK-adopted legislation allowing an exemption for animals that are slaughtered for religious purposes came into force.

The number of chickens being slaughtered without pre-stunning has soared from 3 per cent in 2013 to 18.5 per cent in 2017, the FSA figures also revealed.

British Veterinary Association President Gudrun Ravetz said: "This huge increase in the number of sheep, goats and poultry that are not stunned or not stunned effectively before slaughter is a grave concern to our profession. Millions of individual animals are affected, making this a major animal welfare issue.

"The supply of meat from animals that have not been stunned massively outstrips the demand from the communities for which it is intended and is entering the mainstream market unlabelled.

"In the light of these official figures we reiterate our call for all animals to be stunned before slaughter. If slaughter without stunning is still to be permitted, any meat from this source must be clearly labelled and the supply of non-stun products should be matched with demand."

Welfare at slaughter is one of the UK’s most pressing health and welfare concerns for vets, according to BVA’s latest member survey. The leading body for vets has long campaigned for the re-introduction of law that guarantees all animals are stunned before slaughter on the grounds of animal welfare.

Yet while legislation exists to permit slaughter without pre-stunning, BVA is calling for any meat or fish from this source to be clearly labelled to enable customers to understand the choice they are making when purchasing such products.