Interview: Monica Ali, author

The public's fascination with the Royal family reached its peak with Diana. But, far from being a taboo subject, her sons are determined to keep her memory alive, says author Monica ali

IN most good fairy-tales there is an element of transformation. Poor little put-upon girl in rags metamorphoses into beautiful, rich princess.

Ugly beast, altered by the power of love, becomes his true self: a handsome prince. In real life, you can't help but notice the tendency for the reverse process. The handsome princes who, once you kiss them, suddenly turn into frogs. (Or worse, Jeremy Clarkson.) The Cinderella starlets who find fame then start stamping their foot if their fake tan isn't spread evenly. So perhaps writer Monica Ali captures at least one truth in her latest novel, Untold Story, a reverse fairytale in which a princess – closely modelled on the late Princess Diana – fakes her own death and renounces wealth, position and media attention, to find a more peaceful and anonymous existence in the hicksville town of Kensington, USA. Such is life: good things ain't always what they're cracked up to be.

It is the day after Mother's Day. The Brick Lane author's kitchen in a leafy part of south London is bright and spacious with tell-tale little signs of her two children: the school drawings; the small, exuberant puppy; a Mother's Day bouquet in a vase on the table. Suggesting that Diana, or Lydia as she has become in Ali's tale, would leave her children is perhaps the most controversial aspect of Untold Story. Yet she seems to avoid the directness of the question when asked if she made any efforts to find out how a novel about Diana might be received by the palace or Diana's sons.

Perhaps she's right to blank aspects of that question: should you really have intellectual censorship on writers' inspirations? But what's interesting is that Ali doesn't seem to want to acknowledge – or even recognise – why her story might be contentious because, for her, the fiction is more important than the fact.

"Any subject fits a fiction," she says thoughtfully. "With Diana, so much negative stuff has been written about her over the years and it's the non-fiction stuff that claims to be the truth. If her sons choose to read that, then that might be the stuff that's difficult for them. I drew on Diana, I'm not going to pretend I didn't. But remember, Lydia is a fictional princess and a sympathetic character, I think."

Anyway, while plenty in the establishment would prefer the memory of Diana to die quietly away, Ali continues, her two sons have shown they want the opposite.

William invited inevitable comparisons when he gave his fiance his mother's engagement ring. "When William put that ring on Kate Middleton's finger, Diana had been off the front pages for some time and that brought her back – as William knew full well it would. I saw the gesture as being about how important his mother was to him and still is, and about his love for his fiance. I mean he said it himself … it was his way of including his mother in the day. I thought it was a lovely gesture, a wonderful thing to do, but people even carped about that."

Harry, too, has recently been in the papers, she points out, saying that his mother is in everything he does. "Some people might want Diana never to be mentioned again but I don't see any sign of that with her sons. She's their mother – why would they want her to be forgotten about?"

Ali read a lot about Diana and became riveted by the late princess. Research is always the buffer between a writer and their blank screen but the knowledge gave her a solid foundation of fact on which to build the precarious edifice of fiction. While the details of Diana's life are undisguised in Lydia's story, because Ali's a writer, it's her own fiction she recog- nises. But it's perhaps different for readers who often expect even pure fiction to be thinly disguised autobiography.

The problem in creating a fictional character based on Diana is that the real person left so strong an imprint on public consciousness that it is almost impossible to over-ride that. It's therefore not the Lydia-ness of Lydia, but the Diana-ness of Lydia, that becomes central.

"I think some people will read it as a piece of pure entertainment," says Ali. "It has a thriller element at the end, which is something that I haven't written before. Other people might read it as being about family and identity and the nature of celebrity and what's important in life – and that's fine. People will read it in their own way."

Diana was a divisive figure, Ali recognises that. Some saw her as both hunted and haunted, a victim of her own destructive impulses and those around her. Others saw her as a manipulative egotist. But what most agree is that she changed the monarchy in a way that will impact on the new royal bride. "Diana brought down a faade. She made the royal family human and that's why people are examining Kate Middleton so closely. They are looking for the flesh and blood person that's wrapped up under the blanket of royal protocol. Kate has taken a bit of criticism for keeping quiet. When Diana got married 30 years ago, nobody expected her to do anything but keep quiet."

Hard to know, says Ali, how much Diana directed social change and how much she reflected it. "Diana was partly a precipitator of trends but she was also reflecting the way things were changing in any case, particularly the openness about talking about private emotions. When she spoke about her bulimia, for instance, she brought up a whole raft of issues about eating disorders. I can't imagine John Prescott talking about his bulimia unless Diana had gone first. She made a difference on, say, issues like AIDS and landmines but then, it's hard to disentangle the extent to which she was a reflector of new openness and change, or an accelerator of it. It's always symbiotic, isn't it?"

What she certainly changed was the royals' image. Before Diana, even the young royals seemed like crusty old buffers. "I guess the gap between the royals and ordinary people was once filled with either respect or indifference," says Ali. "They were boring … jigsaws and shooting at Balmoral." But Diana exploded on to the scene with an energy and a glamour that captured a growing – perhaps unhealthy – interest in celebrity. "Some people said Diana was a threat to the institution of the monarchy itself. More recently, she's credited with making the institution more open, more supple, more responsive to public mood. I don't think her impact is so much about revivifying the monarchy as revivifying our interest in the monarchy. That's what's really lasted."

Ali sits across the kitchen table, framed on one side by flowers, a still figure with an intense response to questions, a stare so unwaveringly fixed it can get almost unnerving until it's punctured by her sudden bursts of laughter. She has a warmth, a curiosity about people that is evident in the way she questions as well as answers, and the severity she is sometimes noted for is more a deep thoughtfulness, an attempt to work out her response to things. Questions are good, she says. They force you to analyse your own motives. It makes sense when she says her mother was "a counsellor, incredibly calm and a fantastic listener".

Interesting to analyse, then, the motives of a Booker-nominated author, darling of the intelligentsia, in choosing Diana as a subject. Diana was tabloid fodder. Ali is an Oxford PPE graduate who spent six months last year teaching fiction to postgraduate students in New York. "We all have different sides to us," she says. "Maybe we pretend that we only read The Economist but we all read about celebrities in the newspapers. To my mind it wouldn't even be a sensible detachment not to know what's going on in popular culture."

Ali has written four books: Brick Lane, her highly acclaimed debut about Nazneen, a young immigrant girl trapped in an arranged marriage in Tower Hamlets; Alentejo Blue, a collection of stories set in a Portuguese village; In The Kitchen about a northern chef; and now Untold Story, a fairy-tale about a princess. They might, at first, seem disparate but in fact, they have one common obsession: identity.

In that sense, Diana as a character couldn't be a more natural progression. Diana was transformed, after all, in the way of all good fairy-tales. But she had so many opposing facets to her personality that it is hard to know what was reality and what was construct. She went from pretty-but-ordinary girl next door to sultry style icon. More dangerously, as far as the royals were concerned, she went from Sloaney to sexy, a woman who used her physical allure to prove her own worth.

But as Ali has mused, if she had switched back to an ordinary life in a humdrum American town, what further changes would that have wrought on her personality as she moved into her forties? In fact, Lydia can't escape the loss of her sons and her relationships are limited because she can share her future but not her past. "I felt that I'd found a fascinating subject that was about looking at identity, taking the person out of one context and placing them down in a completely different context. What does that do when you switch someone's environment like that? Are they the same person they were before? What changes? What is different? What do they leave behind? What troubles do they take with them? In other words, what makes us who we are?"

It's an obvious subject for Ali to be interested in, given her background. Her mother is English; her father Pakistani. "I am proud of both parts of my cultural heritage and I feel it's a strength as a writer." It's easy to forget how much of a rebellion her parents' marriage would have been a couple of generations ago and the pairing caused rifts in both families. Ali left Pakistan during the civil war when she was just three years old and has few hard memories of that time. "I think they are inherited memories, really … you hear stories over and over again. I have flash memories of leaving and being in the plane. I remember arriving and my father was not around because he didn't come with us. He was in a refugee camp in Calcutta for nine months so I remember those times as being quite stressful."

In a way, her parents defied their own cultures, in the same manner Diana defied the strictures of hers. Those things send subtle messages to you growing up, sometimes determine what side of the fence you feel yourself to be on. In with the pack, or a rebel on the outside? (There is a character in Brick Lane, a teenage rebel called Shahana, says Ali, and she'll admit to a bit of autobiography there.) Her parents, who live just ten minutes from her, are both strong characters with a well- developed sense of joie de vivre. Their relationship is strong because they had to fight for it. Perhaps it's no surprise, then, that Diana's feisty side appealed to Ali. "She had a rebellious streak I responded to," she admits. "She did stick two fingers up to the Establishment.

She always went her own way. The more I read about her, the more I admired her and the more I liked her."

A lot of women liked that about Diana. The fact that she was so simultaneously fragile, needy and yet gutsy in the face of authority. There was also something in the fact that she was so physically beautiful, yet rejected by her partner, that drew women. (Today, it's Cheryl Cole who draws them for similar reasons.) It was as if looking at a beautiful princess's rejection made ordinary women feel less bad about their own. There were so many dichotomies there, says Ali.

"Diana came from this family of true aristos and then she married into the royal family and became a princess. What does that have to do with the ordinary person? But when she talked about her lonely childhood, her insecurity, her low self-esteem, the troubles in her marriage, infidelity, eating disorders … there wasn't a woman in the country who couldn't relate to something about her. It was extraordinary given her background. She suffered, didn't she? But she didn't curl up and die with it. She reached out."

Identity, Ali notes, is no longer rooted in the old notions about class. "There was a survey recently about class in Britain and apparently 71 per cent of us now identify ourselves as middle class whereas 30 years ago, it was somewhere around 20 per cent. In hard socio-economic terms it's a complete nonsense. It doesn't match with anything. Social mobility has declined. The Gini index which measures inequality distribution, shows we are second behind the US for that, and that is not a race you want to win. But what has changed is how we construct our own sense of who we are. Forget the socio-economic facts, it's about aspiration, interest, aptitudes, the brands we buy, the positions we take, how we feel about ourselves, and class has become about that rather than the old rigid framework."

Despite her aristocratic background, Diana wasn't "royal" enough for some. But since she forced the monarchy to bend towards the people, and the people started pushing themselves upwards out of the working class, perhaps it's no surprise that 30 years after Diana's wedding, Prince William's bride should be the epitome of the English middle classes. But one thing hasn't changed: the media tendency to force public figures into a construct rather than letting them find an imprint of their own making. Will Kate be strong enough to defy that? "We'll have to wait and see," says Ali. "We don't know much about her personality, is my view, but she's on this international stage now and people will be scrutinising her. She seems a level-headed, sensible, head-screwed-on woman who has had ten years to acclimatise to the ways of the world and the pressures she might be under. I wish her luck." There is a sense, from Ali's words, that she thinks Kate Middleton might need it.

The day Diana married, Ali was 13. "I remember piling into a neighbour's front room because she had the biggest telly and it was such a huge event. I had grown up with her in the background and we all watched her transformation over the years."

Untold Story started as a short story but ended up a novel that she delivered to her publisher last July. When Willam and Kate announced their wedding in November, she feared it might be a case of bad timing for her novel. On the contrary, the interest, she says, has been phenomenal.

There are different voices in her tale: the diplomat who helps Princess Lydia escape; her new boyfriend; the tabloid photographer who unearths her ten years later; the female friends who, without knowing Lydia's background, instinctively protect her. "But the heart of it belongs to Lydia and I wanted to make sure the style and tone of it were congruent with her." There are different kinds of writers. "Flaubert says the writer should be like God: everywhere but nowhere visible. And Elmore Leonard has ten top writing rules in which he starts off saying these are my top rules if you want to remain invisible on the page. Now, I can't imagine a writer like Martin Amis wanting to be invisible on the page. He has a very strong voice. But for me, what I am preoccupied with as a writer is not getting my voice on the page but the voice and the personality of the character."

She only started writing after the death of her grandfather when she realised life was finite and she had better get on with it. By then, she had a son (he's now 12 and she also has a ten-year-old daughter) and he woke every hour, turning her into an insomniac who wrote at night. "Writing is hard work. I remember reading an interview with Norman Mailer who said writing a book is so exhausting it takes a piece of you away. When you have finished, there's simply less of you – and that's true. But it's all-engrossing in that you eat, breathe, sleep it and the characters are very real to you in your head. When I am sitting at my desk I don't hear the phone or if the door goes, I am completely lost to it. That's a great thing."

The reviews of Untold Story have been less than ecstatic but a book imagining a thinly disguised Diana faking her own death was always going to be a risky venture. And it's quite nicely ironic if the literary establishment don't like the book much but it sells by the bucket load – as is predicted. You sense a kind of defiance in Ali that her heroine might approve of. "I have to write what interests me," she insists. That is always likely to include aspects of identity. "I know if you set the book up in a line you might think, what's she going to do next?" She laughs. "Well, whatever I like…"

Untold Story by Monica Ali, Doubleday (Transworld), 16.99

• This article was first published in the Scotland on Sunday on April 10, 2011