The method of animal slaughter used by Jews and Muslims should be banned immediately, according to an independent advisory group.
Most butchers have to stun animals first
The Farm Animal Welfare Council (FAWC), which advises the government on how to avoid cruelty to livestock, says the way Kosher and Halal meat is produced causes severe suffering to animals.
Both the Jewish and Muslim religions demand that slaughter is carried out with a single cut to the throat, rather than the more widespread method of stunning with a bolt into the head before slaughter.
Kosher and Halal butchers deny their method of killing animals is cruel and have expressed anger over the recommendation.
One worshipper at the Central London Mosque told BBC Radio 4's Today programme: "Everything about the Islamic way of life is under attack so it makes you wonder if this is actually about humanity to animals."
Peter Jinman, president of the British Veterinary Association said vets respected people's religious beliefs, but urged Muslims to be respectful of animals too.
The brain is instantaneously starved of blood and there is no time to start feeling any pain
Muslim Council of Great Britain
"We're looking at what is acceptable in the moral and ethical society we live in," he told Today.
FAWC said it wanted an end to the exemption currently allowed for Kosher and Halal meat from the legal requirement to stun animals first.
It says cattle can take up to two minutes to bleed to death - amounting to an abuse of the animals.
"This is a major incision into the animal and to say that it doesn't suffer is quite ridiculous," said FAWC chairwoman, Dr Judy MacArthur Clark.
Compassion in World Farming backed the call, saying: "We believe that the law must be changed to require all animals to be stunned before slaughter."
'Way of life'
Muslims and Jews argue that their long established method of slaughter results in a sudden loss of blood from the head, causing animals to feel virtually nothing.
They say they will fight any attempt to prevent a practice required by their religion and central to their way of life.
One rabbi, who had been practicing the Jewish method of animal slaughter for around 40 years, told BBC News: "The process takes a fraction of a second.
"With a very, very sharp knife all the vessels in the neck are severed and that means there's no blood going to the brain and the animal loses consciousness very rapidly and dies soon after that."
The Muslim Council of Britain says animals are not distressed when they are slaughtered.
"It's a sudden and quick haemorrhage. A quick loss of blood pressure and the brain is instantaneously starved of blood and there is no time to start feeling any pain," said spokesman Dr Majid Katme.
The Humanists movement, which has previously called for the abolition of ritual slaughter, said ethical values should be put above religious ones.
"There is no imperative for Muslims or Judaists to eat meat produced in this manner," said spokesman Roy Saich.
"There is no reason why they should not simply abstain from eating meat altogether if they do not wish to eat the same meat as the rest of us."