Britons are inadvertently eating meat from animals slaughtered while they are still conscious, a top vet has warned.

Lord Trees, who is a former president of the Royal College of Veterinary Surgeons, said the meat would mainly be found in pies and ready meals.

There has been a sharp rise in the number of sheep and poultry being killed without being stunned first. This has been attributed to religious practices.

But Lord Trees, a crossbench peer, said it was highly probable that some unstunned meat was entering the ‘standard’ food chain as well.

Britons are inadvertently eating meat from animals slaughtered while they are still conscious, a top vet has warned (file photo)

Writing in the journal Vet Record, he pointed out that many experts were calling for a law change so that all animals had to be stunned before being killed.

The issue is controversial because halal and kosher meat – some, but not all of it, from stunned animals – is an essential part of Muslim and Jewish practices.

Animal welfare charities claim killing animals without stunning them is cruel and causes unnecessary suffering. Muslim and Jewish leaders insist that religious slaughter is just as humane as stunning animals beforehand.

Lord Trees said: ‘It is almost certain that meat which hasn’t been stunned is getting into the normal food chain. Many members of the public are understandably not aware of it.

'There is no doubt a substantial part of the carcass is sold into the normal food chain. Other people will receive that meat in a processed form.

‘It’s very difficult to have accurate traceability when meat may go through the food chain and pass through several different people’s hands. Various parts of it will go in all sorts of directions into different food chains and different processing systems, often different countries. It then emerges as a meat pie or a ready meal or whatever.’

Lord Trees said that killing animals without stunning them beforehand causes ‘pain and discomfort’. In his article he called for all meat to be clearly labelled as ‘stunned’ and ‘non-stunned’ to ensure the public knew what they were buying.

He wrote: ‘While many of us, including the Government and the British Veterinary Association, which has long campaigned on this issue, would prefer that all animals are stunned before slaughter, there are problems in demanding a ban.

Lord Trees, who is a former president of the Royal College of Veterinary Surgeons, said the meat would mainly be found in pies and ready meals (file photo)

‘Labelling should be introduced which clearly defines whether meat is from stunned or non-stunned slaughter. This would help ensure that those who do not want meat from non-stunned animals do not inadvertently eat it.’

Figures from the Foods Standards Agency earlier this month showed the number of sheep slaughtered in Britain without being stunned had doubled in six years, to more than three million.

Raising the matter in the House of Lords, Lord Trees said: ‘Does the minister agree with me that in that aspect of animal welfare we are going backwards?’

In October Lancashire County Council threatened to stop serving halal meat in its schools on the grounds that it was cruel.

The move was put on hold in December after Muslim leaders raised concerns that it would create community tensions.

John Fishwick, president of the British Veterinary Association, said: ‘While non-stun slaughter is still permitted, we believe meat and meat products from non-stun sources should be clearly labelled as such to enable people to make an informed choice about the food they eat.

‘Recent figures on the numbers of animals not stunned before slaughter suggest that meat from these sources is entering the mainstream food market and the provenance of processed meat is particularly difficult to trace.’

A spokesman for the animal rights charity Peta said that not stunning animals before they were killed was only one of the ‘unbearably cruel’ processes of getting meat on to the table.