Media playback is unsupported on your device Media caption Ayanna was taken to Sierra Leone, aged 14, where she underwent Female Genital Mutilation

Every year around 20,000 young women in the UK and France are "at risk" from female genital mutilation (FGM), but the way each country's authorities deal with those who carry it out are very different.

Twenty-three-year-old Ayanna, herself a victim of FGM, stands against the rain-lashed window of her home on the 19th floor of a Glasgow tower block in the Red Road district of the city - home to a new wave of refugees under the government's dispersal programme.

"I am so happy here," she says, clutching her 11-month-old baby to her.

"I no longer suffer the pain of sex with my husband. The pain was worse than childbirth."

She claimed political asylum to escape a forced marriage and to spare her daughter mutilation.

Ayanna explains that other mothers are allowing their daughters to be cut in Glasgow.

"There were two children on the estate, one aged three years and the other two weeks, who were cut recently by the elder women.

"They use razors, scissors and sharp knives".

FGM is a procedure which, at the least, involves cutting away part of the clitoris or, at its most brutal, all the exposed female genitalia, leaving only a small opening for urination and menstruation.

Women can die from its complications; sexual intercourse and child birth can be agonising.

It is accepted practice in parts of Africa and the Middle East and in immigrant communities from those areas. Some believe that it is a necessary part of becoming a woman. There is also a belief that FGM can reduce a woman's libido, and thus the chances of extra-marital sex.

In Glasgow I met a group of Somali women, all of whom had been mutilated.

"If the authorities could help us to make these people stop it, we would be very happy," says one of them.

"Since I arrived two years ago, I have heard nothing," says another. "There should be announcements, classes so people understand what's right and what's wrong."

No prosecutions

Five hundred miles away in Bristol, a group of schoolgirls tell me about "FGM parties".

"They cut them all together, as a group, because it is cheaper and quicker that way," explains 17-year-old Amina.

"At first the girls are all excited because it's a party, until they realise what is going to happen, and then they get frightened.

"It's done by the elder women, or the Imam, whoever is expert at cutting."

Image caption Isabelle Gillete-Faye thinks the UK needs to do more about FGM

About 20,000 children in England and Wales, and about the same number in France, are deemed "at risk" every year.

The laws which made FGM illegal were introduced in France and England at about the same time, in the mid-1980s.

But whereas some 100 parents and practitioners of FGM have been convicted in France, there has never been a single prosecution in the UK.

I meet Isabelle Gillette-Faye, a seasoned campaigner against FGM, at the Gare du Nord in Paris.

She is trying her best not to be rude about the English.

"In England, you are very respectful of your immigrants," she says.

"It is very different in France. They have to integrate and they have to obey our laws."

Detection

She walks me over to the Eurostar platform to tell me the story of two little girls who were about to board the train headed for St. Pancras to be mutilated in the UK.

Female genital mutilation There are three main types: The removal of the tip of the clitoris

Total removal of the clitoris and surrounding labia

The removal of the clitoris and labia and the sewing up of the vagina, leaving only a small opening for urine and menstrual blood - a process known as infibulation

Source: BBC Health

"It was a Friday. We heard just in time. They had tickets for the Saturday.

"A family member tipped us off. We told the police and they were stopped from making the journey."

The parents were cautioned. Had they gone ahead with the mutilations and been found out, they would have been imprisoned for up to 13 years.

"We simply will not tolerate this practice," Isabelle explains.

Does she think many French children have been cut in the UK?

"Yes, because you do not care," she says.

Scotland Yard's specialist in child abuse cases, Commander Simon Foy, disagrees.

"I am not necessarily sure that the availability of a stronger sense of prosecution will change it (the incidence of FGM) for the better."

The trouble is that what Isabelle calls our "respect" and what others call "cultural sensitivity" makes detection in the UK almost impossible.

In France, mothers and babies attend specialist clinics up until the age of six.

The genitalia of baby girls are routinely examined for signs of mutilation.

Dr Amellou, who works in a clinic in a Paris suburb explains that after the age of six, responsibility is handed over to school medical teams.

They continue to inspect girls, especially those coming from those high-risk ethnic groups.

I point out that such a thing would be unacceptable in Britain.

"What is your problem," she asks? "Our interest is in protecting the child."

"If we find a girl has been mutilated, we offer her psychological support and, if she wants it, surgery," she adds.

Reconstructive surgery

At 7am in a clinic on the outskirts of Paris, Dr Foldes is scrubbing up for the first of six operations he is due to perform that day to reverse FGM.

An anaesthetised woman from Guinea Bissau, is wheeled in the operating theatre, her legs are put in stirrups and the doctor begins.

"It will take only half an hour," he explains, "I restore the clitoris and labia, which were sliced off when she was six years old."

What would you do if the girl had blue eyes and blonde hair, would FGM still be carrying on in the UK? Muna, Somali-born schoolgirl

He says this will help the woman enjoy "normal sex and the delivery of a baby".

The patient will pay nothing for this life-changing operation. Dr Foldes operates "pro bono" and the state picks up the costs.

"I have operated on about 50 patients from the UK," he tells me, "but they must pay for everything."

Dr Comfort Momoh, is universally recognised as the UK's expert on the subject. She says that reconstructive surgery is not offered on the NHS.

From her office at St. Thomas's Hospital on London's South Bank, she explains that there are now 17 FGM specialist clinics in the UK.

"We see women who are about to give birth.

"After they are cut, they are sewn up so tightly that the baby cannot get out when they go into labour. We have to cut them open."

With the recent influx of Somali immigrants in to the UK, fleeing the war there, she warns that there are not enough NHS clinics available for what is a growing problem.

"I was in Glasgow recently," she says "and they can't cope."

Back in Bristol, Muna who was born in Somalia and came to Bristol from Sweden in 2003, is baffled as to why the government does not do more to stop it.

"Those statistics show how little the government is doing.

"They are so terrified and they are using cultural sensitivity as a barrier to stop them from really doing anything.

"What would you do if the girl had blue eyes and blonde hair? Would FGM still be carrying on in the UK?"

I ask her if she has a message for David Cameron?

"Yes," she says, "do something about FGM.

"And if you can't handle the issue then there is no point in you doing your job."

Watch Sue Lloyd Roberts's reports about FGM on Newsnight on Monday 23 and Tuesday 24 July 2012 at 2230 BST on BBC Two. Or catch up afterwards on BBC iPlayer or the Newsnight website.