Mariella Frostrup: Everyone's best friend (especially George Clooney)

Did she do it with George Clooney? Sorry, but I just can't get that question out of my head, even as Mariella Frostrup demolishes an acclaimed work of literature in her famously husky voice. "The stuff in italics is dreadful tosh," she says of The Life of Pi. "I don't know how people read it. I started skipping."

This is very bad news for the author, Yann Martel, as it means he is not going to win the Best of the Booker, arguably the most prestigious literary prize ever awarded in this country. The winner will be announced on Thursday, once the public has elected the finest of the 41 novels to have won the Booker Prize. Salman Rushdie is favourite with Midnight's Children, and you can vote online now. But there is a catch. Your own preference – Pi, say, or Amsterdam by Ian McEwan – may not be available for selection.

The contenders have already been cut down to a shortlist of six, by a panel of three judges including Mariella Frostrup. Which is very irritating. And I want to raise it, but I just can't seem to focus on that for thinking reprehensibly rude thoughts about George and Mariella. The twinkly-eyed actor (the most desirable man on the planet, apparently) and the thinking man's thinking woman, who is sitting right here on the sofa in a silky dress, talking dirty prose in those smoky tones. Goodness.

They met nine years ago at the Cannes film festival. The actor and the television presenter. Two creative, liberal people, reputed to be world-class flirts, staying in the same hotel. Both single then, too. They have been chums ever since, in a way that friends say is really quite touching. But did they, you know, touch? Frostrup laughs. "Why should I tell you?"

Because we're mates, aren't we? We go back ... oh, minutes. Frostrup is one of those people with the knack of intimacy, the ability to become – or appear – an instant friend. We must look thick as thieves, huddled in the corner of a members' club in Notting Hill, west London (her natural habitat). But now I remember reading about her working the same magic on other journalists. So is it all an act? I do hope not.

Mariella Frostrup has all the attributes of a potential best pal. That voice makes the 45-year-old sound like someone who has seen the world, could drink you under the table and has stories to tell. Since running away to London as a penniless teenager she has been a rock wife (divorced from Richard Jobson of the Skids by 21) a music business PR (for Live Aid and Comic Relief, among others) a manager (for her friend and fellow former party girl Patsy Kensit) a newspaper agony aunt, an interviewer and a television star. She has the best little black book in town: Gordon and Sarah Brown are long-time mates; she shares an office with Richard Curtis and hangs out with Mick Jagger; and then there is George. People are interested, I argue feebly. "Why should I tell them? I have never talked about my sex life."

Plenty of other people have, I say. She used to be in the gossip columns all the time. She lets out a throaty roar. "I wouldn't tell them if I had sex with John who lives down the road."

Yes, but this is not John. This is George. And anyway, isn't it a bit rich not to want to talk about sex when your own advice column depends on people writing in to confess all? "They volunteer!" And anyway, she says, she writes less about what goes on in the bed, and more about the head. "I recognise my old self in a lot of the letters I get from single women who are unrealistic about what they want." Like marrying and settling down with a certain Hollywood star. "This is a common feminine fantasy," she says, "although he has said on numerous occasions that he wants nothing of the kind." They didn't have that conversation then? "Clearly," she says, laughing, "we were not engaged."

Clearly, though, she was in the market. It was only a few years later that she married the human rights lawyer Jason McCue. They met in the Himalayas, when she was taking a few months out to contemplate life. They now have two young children, Molly and Danny. She had them quite late, but we're not going to discuss that. "I love my children, but I don't really want to talk about them. I'm not that much of a freakish middle-aged mother, I'm just very lucky, and there isn't much more to say. I'd like not to be constantly expected to be a spokesman for things that are part of the natural rhythm of a woman's life."

She would also like not to be judged on her appearance so often. "I hosted a session with Gordon Brown at the Labour conference and the sketchwriters just went on about my blonde hair. Pathetic!" It's not even real, is it? "Of course not. If I ever write a book, it will be called Bottle Blonde."

No more comments about appearance then (although she says she has stubby arms and is unsure about the Orla Kiely dress). But didn't she recently write about her friend George lounging around with his belly spilling over his belt (giving hope to us all)? "He's a god!" she shouts as if to an idiot. "That's what people want to know about." As someone we're used to seeing in a highly polished state on the telly, don't the same rules apply to her? There is a pause. "Well ... yes. They probably do. Apart from the fact that as far as I am concerned, and maybe it's naïve, my career is not in any way attached to the way I look."

No, of course not. She would have got just as far if she'd stayed mousey, been four stone overweight, or had a 'tache on her top lip, right? "Whereas George's career as an actor is very dependent on how he looks. Millions of women the world over want to do foul things to him."

Actually, quite a few men wouldn't mind doing foul – as in quite nice, really – things to her. "Really? Well, where were they when I was single? It's not like I didn't have a door ajar policy!"

She was linked, falsely or not, to some of the most eligible men around, including Chris Evans and Sir Mick. Mostly, she says, they saw her as a pal. Surely lots didn't? "Where were they then? It's safe to say you like me now that I'm settled, because I can't bite!" What does that mean? "If I had wanted to find someone to settle down with sooner, which at one time I probably did, I would have been better off if I'd kept my trap shut more often. Men that aren't threatened by opinionated, faintly aggressive women are in a minority."

In the circumstances, I'm slightly afraid of asking the next question, but it is about books, at least. Who are you, Mariella Frostrup, to tell us what to read? The other judges for Best of the Booker are Victoria Glendinning, the award-winning biographer and critic; and Professor John Mullan of University College, London. Without being rude, what has she got to offer? "I am much more enthusiastic than I am academic," she admits. "But sometimes when people are academic, maybe they miss a bit of that genuine enthusiasm."

She grew up in Ireland, in a house full of books. Her mother was an artist from Scotland, and her father a Norwegian who wrote for the Irish Times. He died of alcohol poisoning when she was just 15. Frostrup was still in shock when she found herself living in a squat in Shepherd's Bush. "Despite the posh tones, I had almost nothing. Even when I was partying a lot, I was also driven by the need to pay the bills."

She broke into TV as a film reviewer but expanded into all kinds of arts and discussion shows. Sexism means it will not last, she says – "look for the women past 40 on mainstream TV" – but for now she is not above doing a voiceover for Marks & Spencer while Myleene Klass cavorts in a bikini. Books are what keep her on screen: she has been canny enough to parlay a surprise invitation on to the Booker panel in 2000 – "I was flabbergasted" – into a leading role in the literary world. Why was she asked? "For the same reason they ask a lot of people who don't have a direct connection with books: to lend a common touch to the proceedings, in terms of books being reader-friendly as well as wonderfully crafted and important."

It is hard to imagine Dame Rebecca West using a phrase like "reader-friendly" when she judged the first Booker in 1969. But as times have changed, so have readers. Faced with an intimidating range of titles, people want a knowledgeable friend who has read everything and has an entertaining opinion. That's what Richard and Judy offer with their book club, and Frostrup provides a slightly upmarket version of the same on her Sky literary show and Radio 4's Open Book.

Critics say she's smug. They say she is soft on the stars. They're missing the point. She is not meant to be overly aggressive or clever: she is meant to be one of us, on a good day, with a better haircut. With that mysterious ability to get on like a house on fire with everyone from academics to Hollywood A-listers. It doesn't seem to be an act. Being a natural great mate has turned out to be a greater asset than even her voice, enabling her to overcome a lack of qualifications and win the power to be ruthless with Pi, Vernon God Little and other winners that people raved about. "Often the amount of noise made at the time has been in direct disproportion to the quality of the book."

Beside her old friend Salman on the shortlist are The Ghost Road by Pat Barker, Oscar and Lucinda by Peter Carey, Disgrace by JM Coetzee, The Siege of Krishnapur by JG Farrell and The Conservationist by Nadine Gordimer. "My discoveries this time were the Farrell and the Gordimer, which I thought was staggeringly brilliant."

So who is going to win? "The public is voting," says Mariella Frostrup. "My money is on the Carey ... and the Coetzee." Not for the first time, she laughs. "Do you know, I absolutely haven't got a clue."

The Best of the Booker: Mariella's verdict on the shortlist

The Ghost Road

by Pat Barker (1995)

I was a huge fan of this trilogy. If it had been written by a man it would have been much more acclaimed.

The Siege of Krishnapur

by JG Farrell (1973)

Inspired, funny but ultimately tragic look at colonialism in India. It has an unusual exuberance.

Oscar and Lucinda

by Peter Carey (1988)

I love him, and this is his most extraordinary book. It's almost a fable, yet it feels modern. Such a compelling tale.

The Conservationist

by Nadine Gordimer (1974)

A man at war with himself and his environment. Surprisingly muscular. It has an aching poignancy.

Disgrace

by JM Coetzee (1999)

One of my favourite books ever. I love the economy of his prose. Such honesty. Humanity in full frontal.

Midnight's Children

by Salman Rushdie (1981)

Launched a whole new way of writing about what was once empire. Mesmerising. You are in the hands of a master.

Vote for your favourite at www.themanbookerprize.com