"It's been a long, long journey I've taken to get where I am today – a liberal-thinking British Muslim woman making a difference"

"It was a torment," she says, explaining that her mother announced that she could fix her stutter by cutting the skin under her tongue, which she insisted was pulling the girl's tongue down in the wrong way. With her daughter-in-law Hanif's assistance, she forced Sameem to the kitchen floor, ordering her to open her mouth.

Ali remembers her oldest sister, Tara, translating her mother's Punjabi words into English as her hand clutching a razor went into Ali's mouth. She also recalls the tearing pain under her tongue as her mother flicked the blade through the tag of skin that held her tongue to the floor of her mouth. She was instructed to stay still but the pain and her revulsion at the taste of her own blood made her fight back. Her mother pinched her hard to keep her still.

To this day, the skin underneath the 39-year-old's tongue hasn't grown back. She opens her mouth to show me – the scar is clearly visible.

And, of course, her stutter didn't go away. The pain was not what most upset Ali most. It was the knowledge that whatever she was to her mother, she wasn't her beloved daughter.

"I longed to be her much loved daughter more than anything else, but she seemed to see me as an object to ridicule, to hurt. I would have done anything to make her love me – even lie down and let her mutilate me," she says, her eyes bright with tears.

It is not the last time Ali will weep as we talk about her childhood. She warns me that there are many things she won't be able to tell me without bursting into tears. The brutal slicing of her tongue was unspeakable, but it was not the only cruelty meted out to her by her family. She describes how her mother and siblings routinely bullied her, beat her with sticks, whipped her and later abducted her from her Glasgow home, selling her into a humiliating forced marriage that left her pregnant at 13, then, when she finally found love and ran away, attempted to kidnap and murder her.

"I could get over almost everything," she says of the abuse she suffered as a little girl. "But not this: I was a defenceless child, and I wanted the one thing my family could not give me. I deserved love. All children deserve to be loved and cherished."

Instead, her family treated her, at best, as their servant. Had she been sold into slavery her lot could not have been more desperate, she writes in Belonging, the shocking account of her stolen childhood that has taken her five years to write.

We meet in Manchester, in the neat terraced house where Ali and her taxi-driver husband, Osghar, 48, have lived for 20 years with their two sons, Azmier, 24, and Asim,19.

Drinking milky tea, she speaks so quietly – stumbling over only the occasional word – that you have to strain to hear her as she tells of the physical and emotional abuse she suffered. "But you know something?" she says brightly. "I am not a victim; I'm a survivor – and I am proud of it." These are words she repeats several times as she reveals why she has chosen to tell her story, every word of which she insists is true, although some identities had to be disguised.

Ali had not talked to anyone about her past until, several years ago, she opened up hesitantly to her next-door neighbour about her violent childhood. Her astonished friend said: "You must have been adopted. No mother would treat her own daughter that way." She suggested that Ali track down her social services file to find out who her real mother was.

A few weeks later, she sat in an anonymous office, tears streaming down her face as she read her own file which revealed that no, she had not been adopted; the little girl, who had a congenital foot deformity, had been taken from her father and placed in a children's home in Cannock Chase, Staffordshire, when she was six months old, apparently after her mother had become ill and returned to Pakistan with Ali's four siblings. Some years later, by which time her mother was back in Britain and had a third son, the family asked for her return.

"I felt as if I'd been mugged by my own past," she writes in Belonging. "I'd so much wanted to be happy about my childhood and I'd thought this was going to be the way I could reclaim those years."

The happy years she clings to are the six and a half she spent in the children's home, where she was cared for by a woman she knew as Auntie Peggy. From time to time her father, who had been diagnosed with mental health problems and was living apart from his wife and children, would visit her, bringing sweets. Sometimes, her sister, Mena, would come and stay at the home with her. "It's the only time in my childhood that I felt safe and well looked after," she says. "It was almost magical. Auntie Peggy was so loving, so kind – I wish I knew if she were still alive today. She was a wonderful woman. Because of her I didn't know anything about fear. I was never cold; I was never hungry."

Ali was taken from the children's home by her mother and eldest brother, Manz, to live with them, his wife, Hanif, and Ali's older sisters, Tara and Mena, and brothers Saber and Salim, in their council house in Walsall. There, she was forced to cook and clean, while everyone about her spoke a language she could not understand. There were no more crisply ironed clothes, no more hot baths, no more bedtime stories. Soon, Ali began self-harming, cutting herself deliberately to draw blood.

"It gave me relief," she says, the tears welling up again. "I didn't do it to hurt myself, it was to experience the feeling. I'd got so used to being beaten, I just wanted to feel pain. It was a liberation, a release."

The only other escape was at school, where Ali, a bright child, loved reading, smuggling home books from the local library to devour by the light of the street-lamp outside the window of the bedroom she and Mena shared, sleeping on mattresses on the floor. Then one day, she came home to find everyone packing. Manz bundled the family into a van and told them he wanted to get to Glasgow that night.

Their new home was a large, shabby ground-floor flat in Pollokshields, near their Aunt Fatima. "I liked it, it was so spacious. The rooms were huge, the ceilings very high. I loved Glasgow. We could be more normal, or so I thought. There were many more Asian people around and Mother at last had some women friends in 'Little Pakistan'. I was still being beaten, still doing all the chores, but I'd a certain amount of freedom in Scotland. The only thing that worried me was when was I going back to school."

Ali would never go to school again. One day, her mother declared: "We're going to Pakistan in October, you won't need school." She even bought her some new clothes for the visit.

In Pakistan, Ali was happy at first. "Best of all, no one hit me," she says. Then she was introduced to Afzal, who was in his late twenties, and was forced into a sham marriage with him. She was such an innocent that when the women in their huge extended family asked if she was expecting yet, she didn't know what they meant. Two months later, she was pregnant. With her mother she returned to Glasgow where her son, Azmier, was born. Alone and terrified in hospital, the 14-year-old didn't have so much as a pair of booties for her baby. No-one came to visit her.

Later, she discovered that her mother had sold her to pay off a large gambling debt incurred by her uncle. "I'd been forced into conceiving this child, but I loved Azmier immediately, fiercely," she says, remembering how she would whisper to him that he would never have to go through what she'd been through.

In Glasgow, Manz bought a hardware store and Mena went to work in it while Ali stayed home with their sickly mother, who nevertheless ruled the household with a rod of iron. Slowly, Ali began to change, standing up for herself and answering back, despite the fact that her brother was beating her, too. When Manz opened a grocery shop on the south side of the city, Ali was made to work long hours there, leaving her son at home with her mother and sister-in-law; she soon discovered that they were beating and starving the three-year-old.

She determined to run away, although the cowed Mena warned her that the family would find her and either kill her or take her back to Pakistan. But then a family friend, Osghar, arrived on a visit. He was handsome and spoke politely and quietly to the 18-year-old, who had just discovered that she and her son were indeed to be sent back to the subcontinent.

Osghar turned out to be Ali's knight in shining armour. They ran away together in November, 1987, settling in Manchester, where a friend of his found them a flat. Six weeks later they married.

Ali's ordeal was not over, though. Forced to leave their flat at short notice, on the day they were moving into their new home the police arrived, bearing shocking news. Three men had been arrested outside the city that afternoon. When their car was searched Ali's name and address were found, along with weapons of restraint, baseball bats and knives. The men confessed that they were acting under orders from Manz to return Ali and her son to Glasgow – if necessary in a body bag.

"He did all that in the name of family 'honour'," she says, disgusted. Manz finally went on trial for conspiracy to kidnap, two months after Ali's second son, Asim, was born. Manz was found guilty, and sentenced to four years in Manchester's Strangeways Prison.

Slowly, Ali and Osghar built a life for themselves, eventually buying their own home. Meanwhile, Ali's mother moved in with her son Salim and his wife in Glasgow, where Salim had opened a butcher's shop. Ali's siblings all remain in Scotland but she has not seen any of them for several years.

While her mother was alive she would visit occasionally. "I even learned to love her, in a way. I made a sort of peace with her before she died. She was a very sick, angry woman, who believed that there was nothing to stop her treating me like a disobedient slave. All I wanted was to love her – and for her to love me."

In 1990, Ali got her first paid job, working in a local immigration office. Then she began studying again, obtaining a certificate in travel and tourism. She set up a residents' association in Moss Side, where she lives, working to secure millions of pounds to give the rundown area a facelift. Last May, she stood as a Labour Party candidate for Moss Side in the local council elections, winning by a landslide.

"I don't say this to boast, but just to record how far I've come," she says. "I asked my brothers and sisters to come and support me – they didn't. That hurt."

One of her major concerns is, inevitably, the issue of forced marriages and so-called honour killings in the Asian community. "I think the government has done a lot with their Forced Marriage Unit, but the change can only come from within our own community. They have to know it's not OK to do this."

Her boys have now left home. Azmier manages a city store and has his own flat around the corner from his parents, while Asim, who would like to write screenplays, is on a media studies course at the University of Central Lancashire in Preston. She shows me their photographs in the family album that she is compiling since she has no childhood snapshots of her own.

She has never fathomed why her mother hated her. Was it because she had wanted another son rather than a third daughter? "No, I don't think so. I believe that it was because I was different – I didn't even look like the rest of my family. My mind was different; I wanted to know about things. Osghar always says that the first time he saw me in Glasgow, 'You were shining. You shone in that family'."

Sameem Ali is an inspirational woman, a woman of great courage. In recent years, she's had surgery for a brain tumour, which thankfully proved benign. "I'm lucky to be alive," she smiles, ever the indomitable spirit. When I remark on this, she asks shyly: "What does indomitable mean? Remember, my schooling stopped at 12, so I don't know any long words."

Now, she's found the words. Despite almost having her tongue cut out as a child and all the other attempts by her family to rob her of her voice, she's telling her story. Her body bears many wounds. "But they're nothing like the ones inside me, the ones that will always be with me. They'll never fade. For me, they are a map, a guide to the past that shows the long, long journey I've taken to get where I am today – a liberal-thinking British Muslim woman making a difference.

"I'm stronger because of all that's happened to me; I've learned to push for what I want now. I have made something of my life, although my memories are not a comfort to me, a place to retreat to; they're a curse. But I have a voice. My tongue will not be stilled."

Belonging, by Sameem Ali, is published by John Murray, priced 12.99.