This lady is also not for turning

IS Gwyneth Paltrow the latest flavour of the month? On the front of the current issue of Vanity Fair she is glammed-up to almost unrecognisable proportions. Then there have been the carefully staged snaps of her with her husband, Coldplay singer Chris Martin, as they leave the hospital. (She is pregnant with her first child.) And now, she is playing the part of anguished American poet Sylvia Plath in the film Sylvia .

But is Paltrow-mania just another Hollywood fling? Julia Roberts had her time in the sun. Is it simply a case of it being Gwyneth's turn, or will the blue-eyed blonde stand the test of time?

Tell me about Gwyneth Paltrow, I ask the writer and director Neil LaBute. She was in his film Possession , based on AS Byatt's novel.)

"Gwyneth is the kind of film actor that directors die for. She's smart, she comes prepared, she understands the power of silence and she's pretty fearless. She also knows how to use her intelligence in an emotional way and that's a rare gift."

Well, that softens the begrudgers' coughs. The blonde has brains. But more than that, she has the sort of attitude which will help her survive the knocks. The 31-year-old is philosophical about it.

"Everybody can't wait for me to fail, because I am supposed to have this perfect life, which is complete nonsense. And then you feel like the tides are turning and it's pick-on-Gwyneth time. I'm just a girl, so that can really get to me. I don't care if I'm not number one, or number five or number 10 - I'm really f**king good at my job and people who are interesting and good know that; and that's all that matters."

In some ways, Paltrow is right to have a kick-ass attitude. Although there are websites set up in praise of "the lovely Gwyneth Paltrow", she is not loved by all. First thing they hold against her is her lineage. Her mother is the Tony Award-winning actress Blythe Danner, who has been around for donkey's years. And her late father, Bruce, was a film and television director. She received early acting tutelage from her parents. So, she was born into the business. If Paltrow was a nobody, people would probably accuse her of having notions above her station. But because she has followed the family tradition, she is regarded as privileged, having all the right connections. And we may as well get her godfather out of the way. He is Steven Spielberg - she calls him Uncle Morty. He took a chance on her and cast her as a young Wendy in Hook . And OK, so he gave her a break. But that wasn't today or yesterday, so how come Paltrow is lasting the pace?

LaBute's line about her being smart and fearless is very telling. You only have to see her on screen as Sylvia Plath to witness her courage. It is an extraordinary performance. She conjures up a young lively Plath and then lets it spiral into deep depression. Like Judi Dench's portrayal of Iris Murdoch, Paltrow surrenders herself to the role. It is not a flattering part, and playing a person with a mental illness is always tricky. In her dark days as Plath, Paltrow has a glazed look in her eyes. It is an authentic performance, so much so that a friend of Plath described the similarity as unnerving.

Two weeks after her father died, Gwyneth was supposed to start working on Sylvia . She thought about dropping out. Playing the tortured, suicidal poet was not going to be a walk in the park at any time, but particularly under those circumstances.

"It was very hard. It was the freshest wound. There were some days I felt broken apart. I'd wake up and the muscles around my ribs were in spasm and I couldn't inhale. Towards the end I was emotionally decimated.

"I don't know how I got through it. It was emotionally incredibly draining and very tough. I was in a very dark place when making the film. I had a lot of overlap with Sylvia and that helped me to play her. It was strange how much our lives overlapped and how a lot of times I would find myself in scenes not being able to tell what was real and what wasn't."

Paltrow confesses that she still misses her father terribly. She still cannot bring herself to delete his number from her mobile phone.

"It has been very hard adjusting to life without him. It's very difficult. I cannot fathom living the rest of my life without my father but I have to. It's my reality and I have to adjust to it. He was incredibly encouraging of both myself and my brother and he was always saying that we could be whatever we wanted to be. We felt we could try anything and risk anything because he would always be there."

But his death has woken her up to life.

"It made me realise that we're all dying and this is all finite. There's no point in wasting time or doing things that are not a challenge or a risk, that don't have integrity or aren't worthwhile - I'd rather not work. Films like Sylvia are not blockbuster material but they make me feel like I'm doing something worthwhile."

Paltrow was not always as wise. She can say this as she has learnt from past experience. Peaking too soon was part of the problem.

"When you reach the pinnacle of your success at 26 years old, as I did [winning the Oscar for Shakespeare in Love] it's not very healthy, because it leaves you in a sort of crisis in terms of what you're supposed to be and do for the rest of your life. I made the mistake of working too much and it turned out to be really the wrong thing. I got to about 29 and was absolutely exhausted and I decided to take some time off. I did Proof in London, which was so fulfilling artistically and re-connected me with why I became an actress in the first place. To remember and re-experience the whole thrill of acting really invigorated me."

When it comes to acting, it is the theatre which separates the actors from the stars. There is no glamour in it, just hard graft. Paltrow earned huge respect for her part in Proof . Charles Spencer, the Daily Telegraph's theatre critic, who is no pushover, was very impressed. "Paltrow plays Catherine with rare grace, powerfully capturing her character's fear and depression without wallowing in it, while also suggesting a lovely underlying sweetness of nature. Those who fell in love with her in Shakespeare in Love will do so all over again."

Unlike so many Hollywood actors, Paltrow does not share her world with the nation. She is cagey about talking to the press and tries to keep her private life private. Her biggest sin, the media has decided, is that she is dull. She and her husband do not drink and eat a macrobiotic diet. And then there is her Ashtanga yoga. The paparazzi snap her coming out of a class with a mat rolled under her arm; not great fodder for the ranks of celebrity-fuelled magazines. She claims that the yoga keeps her strong and centred. So, she is smart and sane. And the only great exclusive on her is that she has impeccable manners. She even sends thank-you cards when she has been a guest in someone's home.

And that's the worst they can say about her?

Gwyneth, you have nothing to worry about.

'Sylvia' opens in cinemas on January 30