A worker at a halal abattoir has been sacked and three others suspended after being filmed breaking strict rules on slaughtering sheep.

The men could face prosecution for the ‘horrifying yet routine abuse’ captured by animal rights campaigners using hidden cameras.

Slaughtermen at the Bowood Lamb abattoir in Thirsk, North Yorkshire, are seen ‘hacking and sawing’ at animals’ throats in apparent contravention of Islamic practice.

The RSPCA slammed the 'absolutely shocking' footage amid renewed calls to ban halal slaughter, which is opposed by the British Veterinary Association and 100,000 people in an online petition.

Sickening: A worker at a halal abattoir has been sacked and three others suspended after being filmed breaking strict rules on slaughtering sheep

Horrifying: The men could face prosecution for the 'routine abuse' captured by animal rights campaigners using secret cameras

Sheep at Bowood Lamb were filmed being kicked, lifted and hurled, with one worker recorded standing on a conscious sheep’s neck.

Staff are also alleged to have erupted in laughter over a sheep bleeding to death with spectacles drawn around her eyes in green paint.

Slaughtermen were allegedly filmed ‘taunting and frightening’ animals by waving knives, smacking them on the head and shouting at them.

And instead of praying as the sheep were killed, the Muslim workers chatted as a radio ‘blared out Christmas songs’ and colleagues sang along.

The footage has been released by Animal Aid campaigners and handed to the Food Standards Agency (FSA) to investigate.

Slaughtermen at the Bowood Lamb abattoir in Thirsk, North Yorkshire, are allegedly seen ‘hacking and sawing’ at animals’ throats in apparent contravention of Islamic practice

Instead of praying as the sheep were killed, the Muslim workers chatted as a radio ‘blared out Christmas songs’

Secretly-placed hidden cameras were used to record practices during slaughter over a period of three days in December.

Kate Fowler, head of campaigns at Animal Aid, said: ‘The vicious attacks on defenceless, frightened animals at Bowood are inexcusable.

‘All four conveyor operators we filmed over three days abused animals to varying degrees, while the slaughterers looked on unmoved.’

She added: ‘This is the 10th slaughterhouse in which we have filmed undercover, and it is the ninth to be caught breaking animal welfare laws.

‘None of the abuses we uncovered would have come to light without our cameras being in place, even though there is a Government-appointed vet at each slaughterhouse.’

The law requires abattoirs to stun animals before slaughter to prevent unnecessary suffering, but there are exemptions for Jewish and Muslim producers.

Slaughtermen were filmed ‘taunting and frightening’ animals by waving knives, smacking them on the head and shouting at them.

Under the halal code, animals are supposed to be killed quickly, with a single sweep of a surgically-sharp knife. They should not see the knife before they are slaughtered, or witness the death of other animals.

The video footage appears to show that these rules were routinely flouted at Bowood, where more than 4,000 sheep were filmed being killed.

The full dossier by the campaigners said:

Sheep were kicked in the face, smashed into solid objects head-first and picked up and hurled by their legs, fleeces, throats and ears

A worker stood on the neck of a conscious sheep, then bounced up and down

Slaughterhouse workers erupted into laughter at a sheep bleeding to death with spectacles drawn around her eyes in green paint

A worker held a sheep by her throat and pulled back a fist as if to punch her

Slaughtermen taunted sheep by waving knives, smacking them on the head and shouting at them

Slaughtermen hacked away at the throats of still-conscious sheep.

Under UK law, slaughtered animals that have not been stunned must remain in position for at least 20 seconds after their throats are cut, to ensure loss of consciousness.

But 86 per cent of the sheep at Bowood were moved before that amount of time had elapsed, some in as little as one second, claimed Animal Aid.

It said many of the practices ‘defied expectations of what Muslims believe halal slaughter should be.’

In one horror killing, it appears that the men erupted in laughter as a sheep bled to death with green spectacles painted around its eyes

Slaughtermen wearing the traditional Muslim kufi skullcap and muttering the words 'Allahu Akbar' (God is great) were allegedly seen breaking rules in the way sheep were put down.

Campaigners said they recognised the risks of stirring up anti-Muslim feeling but ‘witholding release of the footage would be a betrayal of our key mission to expose and combat animal cruelty'.

A petition calling for non-stun slaughter to be banned has reached more than 105,000 signatures.

Set up by organisations including the British Veterinary Association and RSPCA to improve animal welfare, it will now have to be debated by the Commons Backbench Business Committee after crossing the 100,000 threshold.

Last year Prime Minister David Cameron has explicitly ruled out banning non-stun slaughter in a speech to the Israeli parliament.

The findings certainly are abhorrent in Islamic practice, and the abattoir must be subject to the full force of the law Muslim Council of Britain

Kosher food also requires animals to be conscious when they are killed, although Animal Aid said no kosher meat was prepared in the Bowood Lamb slaughterhouse.

Mr Cameron said last year: 'When people challenged Kosher Shechita I have defended it. I fought as a backbench Member of Parliament against the last attempt to do something to change this, and there is no way I’m allowing that to change now I’m Prime Minister – on my watch Shechita is safe in the United Kingdom.'

The Muslim Council of Britain said the video was 'abhorrent' and against everything in Islam.

'Animal cruelty is wrong and criminal wherever it may occur,' a spokesman said. That it is being carried out in halal slaughter makes it even more incredulous.

'The findings certainly are abhorrent in Islamic practice, and the abattoir must be subject to the full force of the law.

'There are urgent questions this case raises: since each abattoir is under veterinarian supervision, how were these practices overlooked? We call on the Food Standards Agency to look into this abuse and the flagrant disregard of the very principles of humane slaughter as a matter of urgency.'

An RSPCA spokesman said the footage from Bowood Lamb appeared to be 'absolutely shocking'.

'The public has a right to expect that all farmed animals have as painless and humane an end to their lives as possible,' she added.

'The RSPCA firmly believes CCTV in slaughterhouses can be a valuable tool to help improve animal welfare.

The law requires abattoirs to stun animals before slaughter to prevent unnecessary suffering, but there are exemptions for Jewish and Muslim producers

Campaigners did not want to stir-up anti-Muslim feeling but felt withholding the footage would be a 'betrayal'

'Our concern [about non-stun slaughter] has nothing to do with the expression of religious belief but with the practice of killing by throat cutting without pre-stunning.

'We believe that meat produced from animals stunned or not stunned before slaughter should be clearly labelled to allow consumer choice.'

The British Veterinary Association said the film was 'truly shocking' and blamed the government for not introducing EU regulations already used in Wales and Scotland.

'The government has delayed the introduction of the EU regulation Welfare of Animals at the Time of Killing (WATOK) which would require slaughterhouses to appoint an animal welfare officer,' a spokesman said.

'These abuses could have been prevented if a welfare officer had been present protecting the welfare of livestock.

'The BVA has long believed that slaughter without pre-stunning unnecessarily compromise animal welfare at the time of death. It affects millions of animals every year and action is long overdue.'

The FSA, which regulates abattoirs, confirmed four slaughtermen have had their licences suspended and an investigation launched.

There is no excuse for treating animals in the way shown on the video and we are therefore investigating the footage with a view to prosecution Food Standards Agency

A spokesman said: ‘The Food Standards Agency takes animal welfare at abattoirs very seriously which is why we immediately suspended the licences of the slaughtermen involved.

‘There is no excuse for treating animals in the way shown on the video and we are therefore investigating the footage with a view to prosecution. We are also continuing to investigate all the circumstances around the incident to ensure proper safeguards are introduced to stop this happening in the future.’

The halal market could be worth as much as £2billion a year, with more than 100 million animals killed using the method annually.

A statement issued by Bowood Lamb's solicitors said: 'Bowood Lamb makes animal welfare its highest priority. We set very high standards for the way in which animals that pass through our premises are treated.

'It is highly regrettable that one of our slaughtermen fell below those standards. As soon as we were aware of this failing we dismissed this staff member for gross misconduct.

'Currently three other members of staff have had their licences suspended because Animal Aid claims that they have committed technical infringements of the regulations relating to religious slaughter.

'We will await the outcome of any investigation relating to their suspension.'

The statement said the real problem was Defra rules relating to animal conveyer belts and attacked Animal Aid for 'breaking into our plant' - a claim the campaigners firmly deny.

'Bowood Lamb is surprised that Animal Aid targeted our premises, given the stated aim of their campaign is to encourage CCTV in abattoirs,' the statement said.

'Bowood Lamb has had CCTV in our premises for over four years.