Yes, the Devil does wear Prada

JOANNA Coles, the English editor-in-chief of the US edition of fashion magazine Marie Claire, is beaming as I enter her office on the 34th floor of Lord Foster's dazzling Hearst Building in Manhattan. The source of her happiness is Giorgio Armani. Coles has just received a letter from the designer thanking her for telling the New York Times that "everyone in New York" showed up to the opening of his new store. A letter from Mr Armani is a rare accolade, she proudly informs me, akin to "a tablet from God".

Hearing her say this, her accent still bearing traces of her Yorkshire upbringing, it's easy to assume that Coles, 46, has been a fashion journalist all her life. She is looking serene in a white Dries Van Noten shirt and an auburn Prada jacket. But, as online snipers were swift to point out upon her ascendancy to Marie Claire three years ago, her working life has mostly been spent in newspapers rather than glossy mags. Though there have been some rough crossings during her time at the helm, simply by retaining her job Coles has proved the doom-mongers wrong. She is now taking centre-stage in Running in Heels, a reality TV show set in the magazine's offices which begins on the Style Network (a US cable channel available on Sky TV) tomorrow night.

The show mostly takes the perspective of three interns at the magazine, but we also see Coles troubleshooting incidents such as Lindsay Lohan threatening not to show up to the magazine's party if posters of the Marie Claire cover she posed for aren't displayed on the red carpet.

So what prompted Coles to let the cameras in? "I grew up with the BBC and the ITV in the 1970s and those incredible fly-on-the-wall documentaries, and I really wanted some of that. I don't have make-up on for half the scenes. I look exhausted and tired, as I do most days. There is quite a lot of reality in there."

Her family - her husband, author and academic Peter Godwin, and their sons Thomas, 10, and Hugo, seven -make cameo appearances. Thomas declared on camera that he is an atheist - "I didn't know he knew the word," says Coles - and Hugo dubbed an omelette his mother made him "revolting". Coles expresses relief this footage never made the final cut.

While Coles ensured the Marie Claire staff get off relatively lightly, the same can't be said for the three young interns, who often appear self-absorbed and do battle with each other over an assortment of trivialities. "I was staggered by how personally they took everything. They seemed to be crying all the time," says Coles. "That shocked me because I've never cried at work and don't really plan on doing so."

Remarks such as this have led to Coles being dubbed the "Simon Cowell of fashion". Is that fair? "I feel like once you're a Brit in America, you're either Tina Brown, Anna Wintour or Simon Cowell," she responds. "The similarity lies in the fact that he says what he thinks and doesn't sugar-coat it I run a magazine, I'm not the school matron."

Rather, Coles comes across in the TV show as a strict but encouraging headmistress. The aura of power she projects is not as absolute as that exuded by Wintour and she's not as buzzy as Brown, but on camera she knows what she's doing.

Barely over a decade ago Coles would have been pontificating about Running in Heels on the defunct Radio 4 media show Medium Wave, which she presented during the 1990s, rather than participating in it.

Yet she insists she's at home in the "complete over-the-topness" that is planet fashion. "It's a huge amount of fun and it's much more Ab Fab [Absolutely Fabulous] than The Devil Wears Prada," she says. "There are days when I really hear Edina's words coming out of my mouth."

Given her hard news background, she could be forgiven for caring far more about the conflict in Darfur than who to choose as Marie Claire cover girl. "My background is the world outside," she admits. "I'm not steeped in fashionbut the more time I spend thinking, learning and knowing about it, the more interesting it becomes."

Coles recently bolstered Marie Claire by adding Project Runway judge Nina Garcia as fashion director: "I'm interested in meeting designers. I like them because they're like a new crowd of creative people for me. I've spent a lot of my life with writers, and designers are the new writers."

But these are perilous times for magazines and Marie Claire is no exception. Circulation has increased under Coles but newsstands now only account for a third of sales and advertising revenue is down year-on-year. She remains bullish. "You can't replicate what we do on the web," Coles insists. "The web is unbelievably useful, but it's not luxurious. I can't take it in the bath with me in the same way." Opening the pages of her magazine, she says, "should be the equivalent of an exhale".

Her own baptism of fire couldn't have been more different from the milieu in which the hapless interns find themselves in Running in Heels. Coles's first job was selling advertising space on The Spectator in the mid-1980s. "They would have their garden party and there would be Bryan Ferry, Mrs Thatcher and the editor of The Guardian. It was an exciting and interesting time to be in England." She then worked for The Daily Telegraph before joining The Guardian, which moved her to Manhattan. She then transferred to The Times as its New York correspondent.

The turning point in her life came in 2001 when she surprised Fleet Street by rejecting the chance to return to London to succeed Matthew Parris as parliamentary sketchwriter of The Times. "I was pregnant and I had a premonition my second child wouldn't sleep," she says. "I was right. I just thought: 'I'm not going to do that job well as it's hard to write funny and light when you're tired."

She also wanted to be shaken out of her comfort zone. "I felt if I moved back to England I would have a great life but it would be utterly predictable. I would be able to work in the British media, which I absolutely loved, but I'd already done that. I knew the kind of house I would live in, I knew who my friends would be and where I would go on holiday. I just could see it all in front of me, and that felt very depressing."

Her adventures in American medialand began as features editor at New York Magazine. Then, in September 2004, she was appointed executive editor of the women's over-forties lifestyle magazine More.

Coles notoriously secured her current position by knocking on the window and hopping inside a car taking Hearst president Cathie Black to JFK airport after a communications mix-up had resulted in their original job interview not happening. "I thought, 'Why can't I ride to the airport with her?' - my training as a journalist was to get the story," she reflects. "I think Cathie thought what an incredibly efficient use of time that would be."

Coles was even approached to edit Playboy magazine ("they did ask if I was interested in doing it I wasn't") and I speculate she's a wonderful networker. "I wouldn't say I was particularly good at it. A friend of mine once said, 'You're very good at office politics, that's why you did so well at The Guardian.' But I did well at The Guardian because I got really great stories for them!"

The key to making it in New York, Coles says, "is to let go a little bit of being British. I don't think the American market is terribly interested in people who arrive thinking that being a Brit is the best thing since sliced bread. You discover Brits who talk about going home to Cornwall. My heart sinks at the idea of a family vacation to Cornwall!"

Coles was initially given a rough reception by some New York fashionistas. Flak proliferated on fashion and media blogs about her outsider status. Her early Marie Claire covers of actresses Maggie Gyllenhaal and a topless Ashley Judd also came under fire. Coles swats away the criticism: "When you're doing the job you're not really taking any notice of what people like that think. I think bloggers have their own community which they think is much bigger than it really is.

"When you're a new editor and people leave because a different boss has come in, the people who leave are annoyed about leaving and want to be negative about it. But that's their prerogative - some people find it difficult to let go so they can be kind of vocal."

But she doesn't regret her early choice of covers. "What you have to do is look at what the covers looked like before you got there and ask yourself: 'Why was I brought in?'"

Coles is an unabashed Obama devotee. "He's an incredibly impressive guy and I think he's the right man at the right time." She has interviewed the President twice and derives inspiration from his relaxed attitude to his opponents. "I'm not in any way trying to compare myself to Barack Obama but one of the things I find very interesting is the way the chatterati are twittering away and he's not taking any notice."

Coles doesn't rule out a move back to England but says the best thing about New York is that she can walk to work and "everything is 15 minutes away in a cab, compared to London where it's so physically big that it's so difficult to get around".

She says she has received TV offers following Running in Heels, among them as a judge on a network show and on a makeover programme. But she's just renewed her contract with Marie Claire "for a decent length of time". However, the day after our interview, it is announced that Marie Claire will replace Elle as editorial partner on Project Runway, the successful US reality show that finds new fashion designers. For now Coles is on a roll, and is sharper than high heels.

* Running in Heels starts on The Style Network (Sky channel 253) tomorrow at 10pm.