A former president of the British Veterinary Association claims that meat producers have increased the number of animals slaughtered according to religious principles, without prior stunning, because it is commercially advantageous for them to do so.

Professor Bill Reilly, a consultant in veterinary public health and former chairman of the UK Advisory Committee on the Microbiological Safety of Food, said the growth in the slaughter of animals which had not been stunned was "unacceptable" and should be curbed, if not banned.

Citing reports by the Farm Animal Welfare Council and EU-funded Dialrel Project, he said films posted on YouTube "clearly demonstrate the pain and distress of obviously still sentient animals after non-stun slaughter".

Although UK and EU legislation allows for the slitting of animals' throats without prior stunning to enable Muslims and Jews to meet the dietary requirements of their faiths, the rapid increase in the production of halal meat in particular now greatly exceeds the proportion of Muslims in the UK population. The halal share of the UK meat market has grown from 11 per cent in 2001 to 25 per cent today, he said. The Muslim population is estimated at 4.6 per cent.

Writing in Veterinary Record, Professor Reilly said: "Why has there been this growth in demand for halal meat and the proportion that is from non-stunned animals? There may be operational advantages for an abattoir if stunning is not carried out. Other commercial drivers include the convenience of not offering a Halal processing line."

Professor Reilly said Britain was a tolerant society and his complaint had "nothing to do with" the expression of religious belief. "The challenge to society is to enable religious slaughter without compromising animal suffering." That meant reducing to a minimum the number of animals killed without pre-stunning.