Every other Friday, Bradford Royal Infirmary's neonatal unit is host to a clutch of swaddled babies, oblivious to the controversy they are creating. Today there are five suckling babes quietly waiting to go under the surgeon's knife. For the moment only a nervous silence suggests the serenity might be short-lived.

How things have changed. In my day there were no waiting rooms, no hospitals, no trained doctors, no anaesthetic, and certainly no aftercare. It's been more than 20 years since my own circumcision at the age of seven but the memory is as painful as if it had been etched in my mind yesterday.

My twin and I were taken to a GP's surgery in Blackburn. I think I went first, a conclusion reached some years later when I realised my inability to recall my brother's piercing cries, just my own, as a strange figure donned gloves while my father and his friend held me down. The rest is a blank, the effect, I would later discover, of passing out. I still hadn't come round by the time they'd pinned my brother down. I only regained consciousness at home hours later to discover my vital region bandaged up and sore.

I'd like to believe the days of the back-street circumcision are long gone. But horror stories still abound: of the occasional glans being excised, of other mutilations and avoidable infections. Many practitioners remain unqualified and the operation is just as likely to be performed on the dining table as in the operating theatre.

Thankfully, change is at hand. In 1996, Bradford NHS trust became the first medical authority to provide a circumcision service. Despite early opposition, a slow uptake and some teething problems, it has now grown to account for a fifth of all neonatal male circumcisions in the city. That however, is only one measure of its success. Perhaps a more telling indi cator is that babies are regularly brought in from as far afield as Newcastle and Hull. Another is that Bradford's model has been adopted by hospitals in Bolton, Bury, Sandwell, and Leicester.

Nafisa Hafeji is a Mancunian but has made the journey across the Pennines with Mustafa, her six-week-old son. The 27-year-old is horrified that her city's 35,000 Muslims still largely rely on untrained GPs to perform what can be a tricky procedure. "I feel much safer about having it performed in a hospital," she says, "you know everything is clean and sterile."

She eyes the clock as it approaches 12.40. At roughly half-hour intervals from now all the babies will be cradled away into the operating theatre. Mustafa is last in line. Nafisa's husband couldn't get the day off work but her mother is on hand to help. They disappear behind a curtain to be shown a video explaining the operation.

Dr Tariq Shah, consultant urologist at BRI and the pioneer of its circumcision service, is doing the explaining. Throughout the day he will be on hand to oversee his nurses perform the operations. Each one has undergone an intensive training programme. Bradford NHS trust makes no bones about its reasons for offering the procedure. Although claims of an overriding health benefit are often made, the medical case for routine male circumcision in the west is at least inconclusive. This service is primarily a religious one.

"Look," says Shah, "there are about 1,000 Muslim male babies born in BRI every year. They all need circumcising. Until now they have been performed privately by GPs but most of them have never had the training. Nor have they been trained to deal with complications. We in the NHS are having to pick up the pieces - and the cost - of these botched operations."

Critics of the service have accused Bradford of introducing circumcision through the back door. The NHS, they point out, is supposed to dispense treatment based on clinical not religious need.

Shah is sensitive to the charge. But for him the matter demands a commonsense approach based on pre-emption and prevention. "Muslims will demand circumcision for cultural and social reasons no matter what. But the NHS can only provide it if medically required. But that would be leaving room for back-street circumcisions, something that would also cost the NHS since it would have to repair the damage they do.

"That's not to say we don't have any complications. But because all our staff are properly trained they don't tend to be as serious. And if there are any problems we can dealwith them swiftly on site."

Circumcisions are not free, but parents pay no more than the cost of materials used in the procedure. At £60 the fee compares favourably with private practitioners. The nurses provide their services for no extra pay.

Our conversation is interrupted by the sound of a baby crying. Next door, Dr Mohammed Ajmal is part-way through an operation. It's uncomfortable viewing but by no-means x-rated stuff. As one nurse comforts the bawling patient and another tugs down his anaesthesised foreskin, Dr Ajmal, a trainee from Manchester, cleans underneath. He then fits a Plastibell, an upturned protective plastic hood, over the head of the penis. The prepuce is drawn over and a cord tightly tied around the foreskin to fit snugly into a groove on the Plastibell underneath.

With the blood supply to the foreskin now cut off, Ajmal makes an inch-long vertical incision in the foreskin and cuts around it in a loop until the skin has been removed. Blood seeps from the cut, but not in the copious quantities I'd imagined. Time for a quick clean, a fresh nappy and the operation is complete. The bell and cord stay in place. Within seven days the part of the prepuce that cannot be cut off will drop off on its own as dead skin.

How much pain is involved is hard to quantify but the medical consensus is that it increases with age. Bradford will only accept patients aged between four and 12 weeks. Older patients, I am told, need greater restraint because the nerve fibres in the foreskin are more sensitive. Younger ones are just too small and fidgety.

Shah concedes the surgery is not pain free but says it is not as bad as people assume. "Babies do not feel that much pain, just some tugging and pressure. They cry as much because they are tied down and detached from their mother."

This is where he is on vulnerable ground. While circumcision does have demonstrable health benefits, the clinical case is far from proven. Opponents see the suffering as unjustified. They call circumcision a "euphemism for genital reduction surgery or genital mutilation performed on children who, by definition are not able to give informed consent". Led by a group called Norm UK, the anti-circumcision lobby says the operation, performed on 20,000-30,000 British infants each year, also causes lasting trauma and feelings of shame and violation.

For Muslims and Jews, the centuries-old rite has traditionally served as a symbol of group identity and a means of ensuring personal hygiene. But this is not, according to Norm UK, sufficient reason for lopping off a part of the anatomy they say is vital to sexual sensation. "We approach the problem from a strictly medical perspective," says secretary David Smith. "It is now acknowledged that it is a damaging operation."

The staff are acutely aware of the ethical debate. Ironically, most, like enrolled nurse Ann Coatsworth, oppose circumcision unless it is clinically necessary. "My son had it done, but for medical reasons," she says. "With any surgical procedure there are risks and you've got to weigh them up. But I understand why other people have different views."

Back in the waiting room the moral controversy could not be further from Nafisa's mind. Her immediate priority is to be reunited with Mustafa, who has been away now for some 20 minutes. Her nerves are on edge. "I'm glad I don't have to go in," she says with a sideways glance at her mother. "I told her she's going to have to change his nappy for the next week. I don't want to see it."

Mustafa returns as quietly as he left. But tears are rolling down his cheeks. Ann lifts up his nappy to rub some petroleum jelly on the treated area, providing the clearly upset Nafisa with her first glimpse of the newly constituted penis.

There's a flurry of activity as Shah enters the room to inspect the other remaining infant. For a moment it seems as though something might be amiss: 40 minutes after his operation, six-week-old Bilal Rehman is still oozing. Ann is instructed to put on a gauze to staunch the flow. The same is recommended for Mustafa. But there are reassuring words from Shah. "It's just precautionary. There will be a bit of clotting, it never gets completely clear."

If there are any unwelcome reactions, the babies will be transferred to the children's ward. Should they still be bleeding half an hour later they will be detained overnight. Tomorrow morning, and again a week later, the parents will be telephoned to check if all is well.

But today is not a day for aberrations. At 3.30, some three hours after he came in, Mustafa is ready to be discharged. His mother greets the news with a sigh of relief. As for the star of the show, his eyes are now dry and he is fast asleep once more.