A summer’s day in 2007, on a film-set in suburban Connecticut, an hour outside Manhattan. Surrounded by a film crew, Kate Winslet is about to act a sex scene with Leonardo DiCaprio. Directing the scene is Sam Mendes – who also happens to be Winslet’s husband. It is the first time they have worked together, and she has been worrying about the scene since they began filming several weeks ago.

Winslet wanted to play this part – April Wheeler in a film of Richard Yates’s 1961 suburban-hell novel, Revolutionary Road – so much that she spent two years persuading Mendes, and then DiCaprio, to do the film. Being driven to the set this morning, she kept thinking, would Leo be put off by Sam? Or would he not care? They are old friends, after all. OK, but if Leo’s relaxed, will Sam feel threatened?

She is still thinking about it as they begin the scene. She asks DiCaprio how he feels. ‘Come on, Kate,’ he says. ‘We’re all grown-ups!’

Mendes is watching them impassively, and says, ‘OK, Leo, press your fingers right into her back, hard!’ Winslet thinks, ‘This is too weird,’ but then DiCaprio digs in his fingers, and she grabs him, and she realises: they are not bothered. The only anxious one is her. But is Sam really OK? ‘Grab her bum, Leo!’ Please let this be over soon, she thinks.

A year and a half later, Winslet is sitting on a large, grey sofa in Mendes’s warehouse-conversion office in Manhattan’s meatpacking district, a short walk away from the loft where they live with their two children, Mia, eight (from Winslet’s first marriage), and Joe, five. She wears suede pumps, skinny jeans, a puff-sleeve top and outsize woollen scarf, all black; her hair is in a ponytail, her make-up minimal. She looks slimmer than you would expect, although in the much-discussed flesh it is her features you notice. They have that strangely proportioned look of actors and models that means off-camera everything looks half a size too big.

She asks Carrie, a young woman who works in the office, to go out for Starbucks lattes. Today is the day after Barack Obama’s election victory – ‘incredibly exciting times,’ as Winslet says, in a voice slightly lowered and abraded by roll-up cigarettes.

‘Sam and I have been explaining to Mia that it wasn’t very long ago that black people weren’t even allowed to vote, and now the president-elect is a black man. Putting it in that context makes sense for a kid. Mia was really blown away by that.’

She sounds strange when she says ‘blown away’, a Disneyland phrase in her London theatreland accent, but then she keeps saying ‘absolutely’ and ‘incredibly’ when we first start talking, so it might be nervousness. She gets very nervous talking to British journalists, she says, because of ‘how tricky the tabloids can be. When I was younger I used to not think about it. I couldn’t articulate what I felt a lot of the time, so I used to say “f***” and “bugger” a lot, and I think that’s how they categorised me: the girl whose weight went up and down, who wore biker boots and smoked rollies, and said “f***” and “bugger” a lot. But I am grown up now, and it’s very important to me to say what I feel.’

Winslet has been nominated for five Oscars (for Sense and Sensibility, Titanic, Iris, Eternal Sunshine of the Spotless Mind and Little Children), but has never won. She makes no secret – just ample, self-deprecating jokes – of her desire to get one. When she appeared in her friend Ricky Gervais’s Extras in 2005, she played herself playing a nun in a Holocaust movie, and explained that a Holocaust movie, like acting ‘a mental’, guaranteed Oscars. It is somewhat ironic that this winter Winslet stars in two films that are tipped to win: in Revolutionary Road as a wife whose husband threatens to send her to a psychiatrist, and in The Reader as a German woman in a 1960s war crimes trial.

In Revolutionary Road, Winslet plays a woman losing her sense of self in a curdling marriage. It is, she says, about ‘the reality and brutality of a marriage, and how if you are unhappy within yourself, regardless of how much you love the person you’re married to, it might result in the demise of your marriage and your life’. Playing opposite DiCaprio for the first time since Titanic, she acts out a long, slow breakdown so convincingly that some early reviewers found it painful to watch – the agonising solitude of suburban unhappiness. By contrast, her character in The Reader, Hanna Schmitz, is suffering her life suddenly being exposed to the public.

The Reader is Stephen Daldry’s film of the 1995 novel, by the German author Bernhard Schlink, that became an international phenomenon because of its articulation of the baby boomer generation’s feelings about the Holocaust. Examining themes of guilt, innocence and language, it tells the story of a relationship between Michael Berg and Hanna Schmitz that begins in the 1950s as a love affair when he is 15 and she 36 and, progressing through an examination of her role in the German war effort, follows them into middle and old age. It is hard to describe the scale and import of the film. Winslet and other actors had to immerse themselves in public records of Nazi atrocities. Many extras were people who had actually attended war trials. The cast includes the best of German acting talent, attracted by the monumental significance of the work. Winslet, playing the final scenes in ageing prosthetics that took seven and a half hours in the make-up chair every morning, requiring a 3.30am start, delivers the best performance of her career.

‘There were just no similarities between us,’ she says of Schmitz, ‘and I couldn’t use anything of my own history in playing her. How much do I understand? How warm can I make her? It was a very difficult balance.’ Usually, she says, she can draw on her own experiences. ‘My baggage… I absolutely do draw on it. Usually in a subconscious way, although I am becoming more aware of it now.’

Born in Reading in 1975, Kate Elizabeth Winslet was the second eldest of four children, three girls and one boy. The family is often described as ‘theatrical’, but this is misleading. Her mother Sally Bridge’s parents had set up the Reading Repertory Theatre Company – Kate’s RP accent comes via Sally from her grandmother, who was in Noël Coward’s class at Italia Conte – and a maternal uncle acted in the West End. Sally herself was a trained nanny, who was working as a matron at Reading’s Blue Coat School for boys when she met Roger, and later worked in a deli. Roger was a circus clown, before training at the Bristol Old Vic to be an actor. Throughout Kate’s childhood he combined acting work with stints as a labourer. Now in his late sixties, he is currently touring as the lead singer of a rock band, Bidgie Reef & the Gas.

The Winslets lived in a three-bedroom house where there was never any money, but lots of noise, fun, food and sharing: ‘Very much a working-class upbringing. I’m from a gaggle of people who do turns at the open mike, or sing along with pub pianists.’ Theatre, then, but in the people’s tradition. She has memories of sitting at the kitchen table testing her father on his lines for a part in Casualty, and the little sisters testing each other on parts for productions at school or the local youth theatre, Foundations. From a young age, Kate and her sisters, Anna and Beth, lived for shows: acting in them, going to London to see them (their favourite: Starlight Express – they saw it five times), getting Sally to make costumes, obsessing over Minipops on television, just enjoying the smell of make-up and the hysteria of the dressing-room.

Other memories that stand out are the October half-terms spent in Cornwall: ‘We went on big holidays with other families, all dogs and harmonicas and barbecues on the beach, and if anyone said, “Look at that sea!”, even if there were no towels and it was blowing a bloody gale, everyone would go in. Women running in bras and petticoats, holding cameras above their heads taking pictures, then everyone coming out… I love that feeling of being vigorously towelled down by your mum after you’ve been in the sea, knowing you’re going back to a baked potato with masses of grated cheese.’ She pauses, smiles thoughtfully at this reminiscence, and pushes a tail of blond hair back behind her right ear. ‘Or chilli con carne. Anyway. That was the sort of childhood I had.’

Sally loved being a mother and was good with children, and like many people with such mothers, you sense that Winslet is torn between the life that stardom has given her and a wish that her children could have the same childhood that she had. She concedes that having children is ‘obviously the most wonderful thing in the world, but also the most knackering’. And she is ‘rubbish at finding time for myself. If I do, I end up feeling guilty. Even if I have a facial I feel indulgent and guilty, because I feel like I should have been doing alphabet charts to stick on the kids’ walls.’ She begins rolling a cigarette. ‘I realise now,’ she adds, ‘that going to work is the one thing I do for me. The experience of acting is very special to me. I love it. I really do enjoy being able to disappear into a private world.’

Aged 11, Winslet persuaded her reluctant parents to send her to Redroofs Theatre School in nearby Maidenhead. She liked it, but didn’t fit in. At her state primary she had been picked on and nicknamed Blubber for being overweight; at stage school, it was for being too close to the teachers. She was neither ‘one of the girls who ran around in lipstick and perfume and did high kicks in the classroom’, nor ‘a suck-up or creep’ (‘I really, really wasn’t!’). But she worked hard and was ambitious; she was head girl for two years. When a girl was upset she would come to cry on Winslet’s shoulder, but a few days later the same girl would join the whole class in turning on her. When she returned from filming the ITV drama Anglo Saxon Attitudes in 1990, all the girls had arranged their desks in a semi-circle around hers, which had been shoved into a corner and engraved with the word bitch.

Victims of bullying tend to become chronic people-pleasers in adulthood, and I wonder if it had that affect on her. ‘A good girl for the grown-ups?’ she answers quickly. ‘Yes. For a very long time, well into my adult years, I couldn’t deal with confrontation at all. I didn’t know how to be honest with people, and would always be apologising. I would do anything I could to avoid conflict of any kind.

I still do to an extent.’ It occurs to me later that this may explain all the self-deprecating jokes about her body, and the eager insistence on being ‘normal’. Whatever the cause, it is effective; I couldn’t find anyone who has worked with her – journalists, PRs, directors, actors – who has a negative word to say. ‘She’s got an astonishing emotional range,’ Daldry says. ‘Loves rehearsing. Loves an investigation. And on set, she is one of the most collaborative and helpful people you could wish to work with.’

Winslet retains much of her family’s raw joie de vivre, which is surprising, because we still tend to see her through English-rose-tinted spectacles. She will talk for hours about the minutiae of sweets (‘my downfall! My favourites are Fruit Salad’). Ditto television talent shows (all-time favourite: Fame Academy). She brings the whole family to London premieres, where they take turns to keep an eye on their father. At the party after the Finding Neverland premiere in 2004, she recounts with gleeful mock-horror, he got drunk, spotted a live microphone on stage, and clambered up to lead a singsong with a crowd that included Mackenzie Crook, Dustin Hoffman and Johnny Depp.

At 15, Winslet was a lead in Dark Season, a BBC children’s science-fiction series written by Russell T Davies. On set she met and fell in love with a co-star, 27-year-old Stephen Tredre. As her career gathered momentum, she left school after her GCSEs (‘I still feel a bit thick sometimes because of that’), and moved into a north London flat with him, aged 17. Two years later she was cast as Juliet Hulme, one of two friends in an obsessive relationship that develops into a murder conspiracy (and based on a true story), in Peter Jackson’s Heavenly Creatures, and everything changed. Suddenly she was one of the most sought-after young actresses in the world, and after several high-profile leads was cast as Rose in James Cameron’s Titanic.

But things were not as they seemed. Tredre was fighting bone cancer. In the spring of 1997 he took the decision to end the relationship so that she would be spared the pain of watching him die. He died in December 1997, as Titanic was opening; she missed the London premiere to attend his funeral.

So just as she was becoming a global superstar, the man she had loved for five years, who had been with her in the transition from a young girl from Reading to a world-famous actress, disappeared. By her own admission, she has never got over his death. ‘You don’t, you learn to live with it. I look back on it and…’ She takes deep breath, her big eyes brimming with tears. ‘Sorry, I still get upset when I talk about it. See?’ She smiles an ironic little smile. ‘My baggage. I absolutely have it.

‘Stephen let me go, and that as an act of love from one human being to another was overwhelming. When I look back, I wish he hadn’t. I wish I had just been there. To the bitter end. He was gone very quickly and – I still go over those moments in my head.’

In fact, even now, every time she and Mendes take a break away somewhere, she will have ‘a big emotional day’ about Tredre, in which Mendes, who is ‘brilliant’ about it, will go over everything with her. ‘I talk about Stephen as if I still love him,’ she says. ‘But I do. I hope I always will.’

Her post-Titanic story is well known. Further blockbuster roles were shunned for smaller productions (Hideous Kinky, Quills, Holy Smoke!, Enigma, The Life of David Gale). She was married at 23, just short of a year after Tredre’s death, to Jim Threapleton, an assistant director whom she met on the set of Hideous Kinky in Morocco. Their daughter, Mia Honey, was born in 2000; their subsequent break-up and tabloid accusations of selfishness and bad mothering came a year later (‘It was awful, because my hormones were still all over the place. It was like being back in the playground being called Blubber’). They divorced in 2001; both parties are bound by a legal agreement not to discuss it. She began her relationship with Sam Mendes shortly after meeting him to discuss her playing parts in his productions of Twelfth Night and Uncle Vanya at the Donmar Warehouse, moved to New York in 2003, remarried and gave birth to Joe in the following year.

To say that her feelings about the 1997-2003 period are mixed is an understatement. Even at the time, she felt that there was too much happening – and too much pressure to deliver as an actress – to discover who she was, but not knowing that made it hard to cope. Now, she seems to think a lot about self-definition, and in our interview occasionally breaks off to consider how she would best sum herself up.

In the entertainment industry there is a theory that celebrity allows you to continue acting the age you were when you first attained it. It explains the boyishness of Take That, the tongue-tied-ness of footballers, the number of cosmetic surgeons in Los Angeles. This is not quite true of Winslet – she takes motherhood too seriously for that – but there is about her a sense of a girl interrupted. She has always felt emotionally different from her peers, and puts this down to having, between 15 and 23, problems she was not ’emotionally equipped’ to deal with. She has an older friend – many of her friends are older – who has a 22-year-old daughter. Kate loves to hear about the daughter’s life, and to think about herself at that age. Recently her friend told her the girl was doing work experience in a hairdressers, ‘and I thought, how amazing – work experience in a hairdressers. What a laugh! Because I didn’t have a laugh… well, I did, and I always make sure I do, but at the same time…’

Work aside, one has the impression that the turning point was her relationship with Mendes. Her conversation, whether about domestic or work life, is peppered with references to him, and several times she mentions his emotional support following shoots. When, for example, she called him from Germany to say she felt drained after filming The Reader, ‘he said, “Just come home and we’ll wrap you up in a blanket, and I’ll pour you a glass of wine, and you don’t have to do anything. We’ll just hang out and watch films, it doesn’t matter.” It’s great having someone who understands like that.’

Working together on Revolutionary Road hasn’t affected their relationship, although they ‘panicked about it, beforehand. You know: “What if we have a row at home and have to go to work the next day?” But if we have a disagreement, we are quite good at getting through it quickly, and being very honest and married about it.’ The best thing, she says, was spending so much time together although, she hastily adds, ‘we were not all “husband-and-wife” on set. Just the odd hug if we needed one.’

In fact, it sounds as if it was she rather than he who set the limits: Mendes was expecting to have lunch with her on set, but she insisted on staying in her trailer during breaks, as is her usual practice. At home, where Mendes usually disengages from work, she couldn’t resist talking to him about her character. ‘I would never usually discuss parts with Sam, but having the director in the house with me was like gold dust. He’s brilliant at switching off, but when I’m acting, I don’t switch off. I think I do, and even when I’m with the kids, they think I have too, but somehow I’m still thinking about it.’

Carrie comes in to say it is two o’clock – half an hour before Winslet has to collect the children from school. Today, though, her new nanny is picking them up (‘I usually do it, and it’s weird getting used to having her to do things like that occasionally. It’s great having an extra pair of hands’) and so we talk a little longer. She says she feels like a different person from the time before she met Mendes – like ‘a grown-up’. As for the future: ‘I’m not very good at planning ahead,’ she says, ‘so I almost never know what I’m doing next. If I’m working on a film, I find it hard to read potential scripts properly.

‘I wonder if I ever had any specific ambitions in the first place,’ she adds thoughtfully, her mind flitting back to childhood shows in Reading. ‘It’s funny, because I am ambitious, but I’ve only ever wanted to do the best I can. I would have been quite happy to be a jobbing actor, you know. It was never about being famous or the best.’

SOURCE:  Daily Telegraph, 12th December 2008, Richard Benson