They are about to be reminded: Styler has a leading role as a Mrs Robinson type in Love Soup, a flagship drama for the autumn schedules that’s being talked up as BBC1’s answer to Frasier. “Hmm, I think it’s a bit Woody Allen,” she says, sipping serenely at a giant cup of earl grey tea in her film-production office, which overlooks London’s Green Park. “You know, humans not getting each other right.”

Styler’s look is modern hippie executive: size 27 Notify jeans (on a frighteningly supple-looking body for a 50-year-old), a low-slung Celine belt (a present from Sting), a black Chanel tweed jacket and Gaultier cowboy boots. (She also loves Roland Mouret and Dolce & Gabbana.) She wears no make-up and has unbrushed hair, unpainted but manicured nails and the most perfect eyebrows in the universe. It’s her own face: she underwent plastic surgery in her teens, after a car accident as a toddler — she was called Scarface at primary school — but has had nothing done since.

Translucent skin and Dietrich cheekbones come naturally when you do two hours a day of yoga and meditation, although, satisfyingly, she is not as perfect as she seems. She has to have a daily visit from a trainer to force her halo on: “I could do the yoga on my own, but I would be too tempted to do e-mail or get on the phone.”

Surprisingly small and shy, Styler becomes more animated as she talks about her new project. Her character is called Irene: “She is going through a troubled patch in her marriage and has a penchant for men half her age.” She giggles flirtatiously, suppressing a wink, and as she does so, I realise she is one of those envy-inducing people who are effortlessly charismatic and attractive. Despite her po-faced ecowarrior reputation, she also has a sense of humour. (Someone on set says she is “a real laugh”.)

People forget that in 1977, when she first met Sting, now 53, she was better known than he was. “I used to be on telly — a lot,” she smiles. Back then he was in the Police, an unknown band with no recording contract. She had a role in the Cornish bodice-ripper television drama Poldark, playing Emma Tregirls, the gypsy girl who falls in love with the preacher.

She won a scholarship to Bristol Old Vic Theatre School as a teenager (going against her father, a factory worker, who thought she should get a proper job) and worked her way through rep to acting in the West End in Macbeth, starring Peter O’Toole. One of her last big theatre roles — before her relationship with Sting went public — was in an RSC production of Iris Murdoch’s The Bell, in 1981. Yet as soon as she became known as Sting’s other half, things went wrong. So why give up acting? “I never gave it up. I rather felt that it gave me up. There were not so many choices. I’d been quite successful very young. Then, in my early twenties, when I’d just had Jake born in 1985, everything seemed to dry up. I had a bit of a crisis, being at home and festering and waiting for phone calls. Going up for things and not getting them. It was just becoming untenable. I was always waiting for the phone to ring, and it didn’t.”

Styler decided that she needed her own projects: “That’s why I became a producer. It became apparent that I should get into the driving seat, and that set off a whole lot of stuff that has given me a much more fulfilling life.”

And it is all the stuff she is now better known for. There is the Rainforest Foundation, set up in 1989, whose annual zillion-dollar Manhattan fundraisers she organises. Her production company, Xingu Films, has offices in London and New York and churns out feature films and documentaries. (She says she is banned from China because of her involvement in Moving the Mountain, an award-winning documentary about Tiananmen Square.)

Having her own business has allowed her to organise her own time. As a result, she says, she is closer to her children Mickey, 21, Jake, 19, Coco, 15, and Giacomo, 10. (She is also stepmother to Joe, 29, and Kate, 23, from Sting’s first marriage, to the actress Frances Tomelty, who was with him when he met Trudie.)

She must be a driven person. After all, would you do anything if you were married to Sting? This, she says, is something she inherited from her mother, who believed in being busy. She grew up on a remote council estate in Stoke Prior, a village on the Worcester and Birmingham canal. Her father worked in a lamp-shade factory and grew his own vegetables. Her mother was a dinner lady. “She went to do school dinners so that she could be closer to us. It was a rural community where you joined in with what was around you. She was a very kind person, she had a lot of compassion. She wanted to give of herself. And make jam.”

The family didn’t have a fridge when Styler was young, and as a result she has been obsessed with fresh, natural produce since long before organic was fashionable. Now she presides over her own smallholding at Lake House, the Wiltshire pile that she and Sting own, and an estate in Italy that produces organic honey and olive oil (as well as slightly more urban homes in London, LA and New York). “I had a simple diet as a child, and I’ve never liked the idea of food that has been on the shelf for too long. I am not the hands-on person who is harvesting the olives and picking the grapes, but I am very ideas-driven.” Harrods has just bought up her Italian range, Il Palagio.

She constantly describes herself as privileged and fortunate — “I’m lucky enough to be able to choose great things to do” — and virtually apologises for having several homes. “I like to feel that I’m part of another country, not just a guest there. There is a lot of pressure taken off you by having a home and not having to do hotels with your children.” Because of Sting’s commitments, she is always on the move. She jokes that she knows the Italian and French for “Push, please” because she gave birth in both countries while Sting was on tour. Doesn’ t the travelling bother her? “Well, we’ve been together for more than 20 years now, so I’m used to it.” Most of the time these days, she is at their home in London (near her office) or in Wiltshire.

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