But she also confessed: "My sisters won't be reading the book. They have their memories of our father. I accept that. But this is my story."

News of the sensational claims, which will be revealed in her autobiography, Anne's Song, published later this month, have shaken Blackpool's entertainment fraternity.

Other members of the family refused to comment this week.

Father-of-eight Tommy Nolan senior, who died in 1998, was held in high regard as a tough but fair taskmaster who, with his wife Maureen, established the showbiz dynasty in the '60s.

The Nolan Sisters were a worldwide success through the '70s and '80s – touring with Frank Sinatra and at one point even outselling the Beatles.

The parents, known as the Sweetheart Singers, moved from Dublin to Blackpool in 1962.

The Nolan Sisters I'm In the Mood For Dancing later became a number one hit in the UK and international charts.

But in exposing the darkest secret at the heart of the clean-living clan regarded as showbiz royalty in the resort, Anne has blackened her late father's name and admits she has to live with it.

She says: "It's difficult but I'll live with it. I've lived with far worse. Abuse, breast cancer, my marriage breaking up. You either get on with it or go under."

Anne, who now works at the office of the Official Receiver, says she began writing her autobiography four to five years ago.

"I'd been working on it for some time. I read A Boy Called It and couldn't understand how people couldn't see how he was being abused, there were so many visible signs. In my case it was all concealed.

"Then I read autobiographies by bits of kids who really hadn't had a life and I thought I've had a more interesting life. So I decided to tell my story. And, like it or not, this is part of my story. What happened, happened."

She chose to open up on her private life after her divorce from former professional footballer Brian Wilson last summer and after her mother's death late last year, having suffered Alzheimer's for four years.

"This would have killed my mother otherwise. She loved my father."
Anne, who has signed an exclusive serialisation deal with a national Sunday newspaper, says she told her sisters of the abuse after her father's death. In 1998 he had the showbiz equivalent of a state funeral.

"I kept hearing what a great guy my father was and knew differently. There was this other side of him. And it wasn't just sexual abuse. He was very controlling. He killed stone-dead the love I should have felt for him. My sisters were very shocked when I told them.

"It hasn't killed my faith. I still pray. But I never confessed what was happening. I never let what happened spoil everything but it's always there. I've still had a fantastic life."

Anne says her strict Catholic upbringing was blighted by repeated sexual abuse by the father her younger sisters Denise, Linda, Maureen, Bernadette and Coleen trusted implicitly and "adore" to this day. They also have two brothers Tommy and Brian.

Anne, the oldest sister, believes she was singled out because she was the last to join the clan in Blackpool.

"I had been in hospital for a year and a half with suspected rheumatic fever so couldn't come with the family to Blackpool when they moved."

She says she was 11 when the abuse started, after being left alone with her dad and her younger sister Bernie (Tommy and Maureen's second youngest daughter) who "wasn't yet two."

It ended when she was 15 or 16. At one point Anne claims he suggested they run away together and set up as man and wife.

"I felt real revulsion. I never spoke of it to others. I felt in some way it was my fault. I was a child. I was very innocent. I didn't know what was happening to me. I never told my mother about it."

But she believes the skeleton in the family closet ultimately undermined her 27-year marriage to Brian.

"He was the first person I ever told. We had been married 24 years before things started to go wrong."

Anne says Brian put the break-up down to the guilt he felt - at placing their two daughters at risk by leaving them with her father.

"He said he could not live with the guilt that we both placed our daughters in jeopardy by leaving them with my dad to babysit.

"In fact we would leave our daughters with my mother but if she went out, my dad would look after them. Nothing happened to them. I think it began and ended with me."

Anne says their divorce came through last summer on what would have been their 28th wedding anniversary.

"I found it very hard to cope with. I know people get married and get divorced all the time but I got married, in the Catholic church, and I said my vows and meant them.

"It was a difficult time and I became suicidal when my marriage broke up. I still loved my husband but I think Brian just fell out of love with me."

Anne says there is nobody else in her life today. She has also denied rumours of a rift within the family created by her decision to reveal the abuse.

"I am still very close to my sisters. A couple have said they won't read the book. They loved my dad and don't want to think about him as being that kind of person.

"But they haven't put any pressure on me not to say what happened. I have my own memories of childhood and what happened was a massive part of my life.

"My daughters, Amy, who's 27, and Alex, who's 20, are there for me, too. They now see their grandfather with different eyes. And people keep telling me I've been so brave but I don't see it being brave at all.

"But I would say this – if there's anyone out there now, going through what I went through as a child, please don't keep it to yourself, but tell someone. Don't suffer in silence."

* Anne's Song, by Anne Nolan with Richard Barber, is published by Arrow Books on March 27, at £12.99