An undercover video of a halal abattoir, where animals are killed for Muslim consumption, has sparked outrage as it shows slaughtermen hacking at sheep's throats and kicking animals in the head. It has prompted some to call for the religious slaughter of animals – in which they are conscious immediately before death – to be banned. Others say it's religious discrimination, and that being able to keep dietary laws is a fundamental element in being able to practise a faith freely.

Hmm, Muslims – it sounds as though this might be the wolf of prejudice dressed up in the sheep's clothing of animal welfare.

We'll come to that. But it's important to realise that it isn't just about Muslims; this affects Jews as well, who also have strict laws about slaughtering food. Muslims require food to be 'halal' and Jews 'shechita'. Both involve methods of slaughter that mean the animal has to be conscious before it is killed, that is not stunned first, which is the usual method in British slaughterhouses.

Why is it such an issue?

These are two religions which place great value on observing dietary laws. Some foods can't be eaten at all and meat has to be from animals correctly killed. It's sometimes hard for Christians to grasp how important it is because we don't have dietary laws ourselves, but it is part of what identifies a Muslim as a Muslim or a Jew as a Jew, not just to outsiders but to themselves. Muslims believe the rules derive from the Qu'ran; Jews from book of Deuteronomy. If you are serious about your faith you will do what your scriptures say.

I have a feeling I'm not going to enjoy the next bit, but – what exactly are we talking about here?

Breathe deeply. The name for the halal method of slaughter is 'dhabiha'. Animals are killed with a swift incision to the throat from a razor sharp blade. The animal must never see another animal being slaughtered nor must it ever see the blade being sharpened. They must be checked before slaughter to ensure they are healthy and given clean water to drink. Then they are turned to face Mecca, the prayer Bismillahi-Allahu Akbar is recited, the jugular vein and carotid arteries are cut – leaving the spinal cord intact – and the blood drained from the carcass. Shechita, carried out by a shoket, involves a super-sharp blade called a chalaf being used to sever the throat. The blood is then drained.

It sounds a bit gory, compared with the proper Christian way of killing things.

Allow me to disabuse you of that quaint idea; breathe deeply again. Campaigners against religious slaughter argue that stunning the animal first is kinder. Different methods are used: gas stunning, which slowly renders the creature unconscious (though birds and pigs are actually killed like this too); percussive stunning, used for cattle and sheep, in which a captive bolt is used to render it unconscious before it's hoisted into the air by one leg and stuck by the slaughterman; and electrical stunning, which involves passing a current through the brain. For sheep, this means shocking them with tongs on their heads; for birds, it involves hanging them by the feet and dipping them in an electrified water bath before the belt moves them on to a mechanical neck-cutter.

You seem to be saying that there is no nice way of doing this.

Yes. A cow is not born beef, it has to become so.

So there's really not much to choose between the different methods, as far as the animal is concerned?

It depends on who you listen to. Defenders of religious slaughter argue that the procedure is so quick that it's painless. On the other hand, the RSPCA cites a Farm Welfare Council report which concludes that animals do feel "very significant pain and distress" and says that "slaughter without pre-stunning is unacceptable and that the Government should repeal the current exemption".

However, campaigners point out that stunning or not stunning is only one aspect of animal welfare, and arguably not the most important. There are calls for CCTV cameras to be installed in all slaughterhouses to monitor the behaviour of staff, measures to reduce pre-killing pain and fear, and a concentration on animal welfare up to the very last moment of life. So arguably, if Qu'ranic principles were actually followed, the animal would have a reasonably good death.

Is there any room for compromise, religiously?

Not for the shechita; the animal has to be conscious. However, one of the certifying bodies for halal food, the Halal Food Authority, does allow electrical stunning for sheep and poultry as long as the animal doesn't die. The Food Standards Agency estimates that 88 per cent of animals killed by halal methods were pre-stunned.

Why do some people want halal meat labelled in supermarkets?

The RSPCA is campaigning for it because says people ought to be able to choose. However, Muslims worry that it is both stigmatising and divisive, implying that they don't care about animals. Both of these statements are true.

So is it all about prejudice against Muslims?

No. Lots of people really do believe that not stunning animals before killing them is cruel. The fact that this most recent scandal is in a halal abattoir is completely irrelevant; all slaughterhouses need to be accountable and to have the highest possible standards of welfare. The trouble is that many Muslims and Jews genuinely don't believe it's cruel, and see it as a crucial part of being faithful to their faith. So it is up to society to decide whether the difference to the animal of stunning or not stunning is sufficiently great to justify making it impossible for large numbers of people to practise their faith in the way they believe is right. So far the 'religious exemption' to stunning has held.

A final question: I'm a Christian, should I worry about eating halal meat from a religious point of view?

You are thinking about 'meat offered to idols' in the New Testament, and the fact that a prayer to Allah is made as each animal is killed. In short, no. In the ancient world it seems that there was a similar practice at slaughter, and some Christians had tender consciences about it. Paul is not entirely consistent in his counsel, but in general he seems to say, don't worry about it. Elsewhere (eg Acts 15 and Revelation 2) a different line is taken, but this seems to reflect local issues.

I'm thinking of becoming a vegetarian.

You and me both.