Interview: Mary Portas, retail guru

• Portrait by Graham Jepson

The style icon and retail guru answers her Maida Vale door, nearly six foot tall in heels, looking like a fashion superhero. There's just something about Mary Portas. At 49 she looks unbelievable in a grey ruffled mini-dress, fuchsia tights, rings like bejewelled gobstoppers and dominatrix-style black leather ankle boots, topped off with a razor-sharp gingery bob.

In fact, everything about Portas is razor sharp: from her haircut to her tailoring, her cheekbones to her tongue. She is the woman who, with her no-nonsense style, turned around the fortunes of Harvey Nichols in the 1990s and who has since offered her expertise to countless small businesses through her popular BBC2 series Mary Queen of Shops, wherein she makes over independent retailers whose bank balances are heading for the red.

This year, she turned her attention to charity shops, overhauling the Orpington branch of Save the Children – which had been taking just 900 a week – as part of a three-part series called Mary Queen of Charity Shops. She opened a pop-up charity shop in Westfield Shopping Centre in London, helping the till ring to the tune of 190,000 in just three weeks; and now she's taking the formula to Edinburgh, where a new branch of Save the Children opens today on Raeburn Place in Stockbridge, in a former HBoS building.

This will be Portas's first permanent boutique-style charity shop. An ambassador for Save the Children, she plans to open four more outlets across the UK, following the template of the Edinburgh branch. Dubbed the Living and Giving shop, it will sell a range of designer bargains and high-end high-street attire.

Charity shops have something of a bad name. We may dream of finding an elusive Chanel tweed jacket, a perfect piece of cashmere, or a flawless Alaia dress in our size, but too often what we're confronted with is a saggy scrap of lilac nylon masquerading unconvincingly as clothing.

You can expect a lot more from a Portas project. Some of the stock in the Stockbridge boutique has been donated by celebrities including Jamie Oliver, Peaches Geldof and Lauren Laverne, and the weekly fashion bible Grazia will be topping up the rails with selected designer pieces. Moreover, shoppers who bring along quality clothing to donate to the store, and who are therefore designated "shopping neutral", will jump to the front of the queue.

After inviting me into her colourful home, Portas folds herself up neatly on a squishy sofa in her smart living room. Her partner, Melanie Rickey, the fashion features director at Grazia who is helping to co-ordinate and price all the stock for the Edinburgh store, is working frantically in the adjacent room. Portas's two children – Verity, 13 and Mylo, 15, (from her 13-year marriage to ex-husband Graham, with whom she is on excellent terms) are at school, and the family's dog, Walter, a waggy, scruffy little thing, is curled up next to her.

"The Scots, I think, have a great kind of wonderful, individual way of styling themselves," she says, clasping her hands together and widening her eyes. Her voice is loud, booming almost. She is witty, passionate and brusque.

"You're not afraid to be a bit different," she continues, "and you tend to have that wonderful eclectic mix of fashion that gives you the confidence to shop at charity shops. That was one of the issues that I had in getting people to wear fashion from charity shops.

"You have to have a sense of your own style, to choose and edit. It's just too easy to slavishly go into a branch of Primark and take anything off the shelf and just be the same as everyone else. But to go in and pick things and pull your look together takes confidence. I think you have that confidence."

The P-word is a dirty word in the Portas household. It's immediately apparent that she loathes the likes of Primark and other "value" retailers. Seeing people leaving such stores laden with bags of cheap clothes exasperates her, and she's particularly frustrated by the way they rival charity shops with their pricing.

"Ten years ago clothing was more expensive than it is today," she says. "That just tells you that we're mass-producing, we're over-producing and someone, somewhere is doing it all for sweet FA. And that Primark thing, 'we're doing value for the consumer', oh, don't give me that …

"Charity shops used to be for people who couldn't afford to buy much, and the value retailers have taken their business to an extent. I think culturally it's more the middle classes who are using charity shops now.

"The value retailers have taken their place (for those with less cash] and given themselves an avuncular umbrella to do so. I don't believe a word of it! And you stand at a Primark door; do you ever see anyone come out with one small bag? No, loads. Loads. Loads … The biggest thing I'm up against is value retailers."

With concerns for the environment looming ever larger, and the recession still hanging over our heads, Portas predicts that we are set to fall in love with charity shops all over again, however.

"I think it's clever to shop in charity shops and I think there is a return from consumers to a more intelligent way of shopping," she says. "We've gone through 15 years of really high consumption where fast fashion and very cheap value fashion affected people's shopping habits. And now, with the financial crisis and the environmental crisis, there's a slower way that people are consuming and there's a more sophisticated approach to consumerism. So to me charity shops are like, whoopeedoo!"

She raises her clenched fists in celebration, as if she's thankful that consumers have cottoned on at last to what she's known all along: that charity shops are a no-brainer. "Here we have a chance to do something where everybody wins," she says, smacking her knee decisively. "People give and people recycle and people end up giving to charity and getting something at a really good price in the process. It's one of those lovely business models."

Portas certainly has an eye for a good business model. Orphaned at 18, the fourth of five children, she got her first job in retail at John Lewis in 1978, becoming a window dresser for Harrods in 1982 and moving on to Topshop's flagship Oxford Circus store in the late 1980s. Her first big triumph came in 1990 when she moved to Harvey Nichols and transformed it from a fusty department store into an emporium to upmarket consumerism.

Just how did she turn Harvey Nicks around? Through edgy window displays, employing up-and-coming designers and, perhaps most importantly, by persuading Jennifer Saunders to namecheck the store repeatedly in cult 1990s fashion sitcom Absolutely Fabulous.

Today Portas runs the London-based retail consultancy Yellow Door, which employs 40 staff and counts Louis Vuitton, Miss Selfridge, Oasis, Mulberry and French Connection among its clients.

She works a strict nine-to-five day, partly because her own family life was cut short when she was just a teenager, and prioritises Melanie and her children. She tells me how she missed a meeting with Armani, a potential client, because it was Mylo's sports day, and insists simply that: "The people who won't let you put your kids first are not the people you want to work with."

Thirteen-year-old Verity is already following in her mother's footsteps. She loves hunting for bargains in charity shops, and if she does head for the high street, her mother insists that she clears out her wardrobe and gives something unwanted to a charity shop first, so she remains shopping neutral.

Portas beams as she tells me how Verity returned home from a charity shop shopping expedition recently with a "fabulous" checked Moschino shirt, which she promptly donned for Halloween, dressing as a member of the Village People. I wonder if Portas could have been any prouder if her daughter had returned home with an A on her report card.

"Charity shops were always part of my life," she says, matter-of-factly. "I remember my mother would buy presents for us from the charity shop. And I would think nothing of opening up a Christmas present and knowing it was second-hand.

"I can't remember ever getting brand-new board games. You were always getting a second-hand Monopoly or Cluedo set and it was always missing something or other but it was just the way I grew up."

Of course, being the savvy retail guru she is, Portas knows that when charity shops are up against cheap retailers they can't afford to be putting out clothing that's the sartorial equivalent of a Cluedo set with a missing Colonel Mustard.

"The most important thing is stock," she says. "I'm very keen on shopping environments, but if the product's sh*t you're not going to get anyone going anyway.

"However, we need to create something that's not trying to copy the high street. If you try to look like the high street you're always going to be the knackered ones, because you haven't got the budget." The solution, she says, is to "use the environment and the money that you do have to be quirky and individual."

So what's next on the agenda for Mary Portas? There's always something next on the agenda, she laughs, telling me that her best friend will phone her up and ask: "So what are you doing now?" Next up she'll be working on something she calls "V Day" – encouraging the public to get volunteering and young designers to start selling their creations in her charity shops, splitting the profits with Save the Children.

She launches into a speech instructing the people of Edinburgh to get behind the Stockbridge branch of Save the Children by donating their wares.

"What we need is to get Edinburgh behind this Living and Giving shop," she says, and it's more of an instruction than a suggestion. "We need to get people in Edinburgh donating their stuff. I want to see how much they're willing to take out of their cupboards and into the shop. This is absolutely what it's about. I say to people, first of all, fundamentally: clear out. It's just the most wonderful thing to do. We all have far too much, so… Clear. Your. Bloody. Closets. Out."

Well, people of Edinburgh, Mary, Queen of Shops has spoken. She has called you to arms. Will you answer? Certainly, I'll be doing my duty when the shop opens at 10am today, my unwanted clothes in hand. After an afternoon in the company of this extraordinary woman, all I can say is: 'All hail the Queen.'

Mary Portas's Living and Giving shop for Save the Children opens today, 34 Raeburn Place, Stockbridge, Edinburgh. Tel: 0131-315 2856, www.savethechildren.org.uk

This article first appeared in The Scotsman Magazine on 21 November 2009.