Halal food is everywhere. According to recent news reports, it might have been "secretly" snuck into your sandwich at a football match or fed to your "unwitting" child in their school dinner. It's also found in hospital canteens, pubs and sporting venues. But what is this frightening food that the Mail on Sunday proclaims is being "prepared in accordance with Sharia law"?

The definition of halal is anything that is legal or lawful for Muslims. In terms of meat, this can apply to what kind of animal is used (not pigs, for instance) and the way they are killed: an animal must be healthy, the butcher must make a recitation dedicating it to God, and the jugular vein, carotid artery and windpipe are cut with a single swipe from a sharp knife. As with kosher meat, the idea is that the animal dies immediately and the blood drains away. Animal rights groups have been quoted this week saying that "the suffering caused by this form of slaughter is . . . severe".

Yet things are not as simple as they seem. Shimon Cohen, from Shechita UK, a group set up to promote awareness of Jewish methods of slaughter, and Ruksana Shain, from behalal.org, insist that cutting an individual animal's throat in a single swipe is less cruel than stunning it first by driving a bolt into its skull, gassing it or electrocuting it. Despite this, the halal food authority, which certifies meat for outlets such as KFC, controversially allows animals that are stunned before being killed to be certified as halal. And, according to an RSPCA fact sheet, 90% of animals killed for halal food in 2004 were stunned first. As in mainstream food production, the animal's throat is then cut.

So this supposedly sinister method, it seems, is not that different after all. What the RSPCA, halal groups and kosher experts all agree on is that better labelling is needed so consumers know how their food has been prepared.