It is terribly embarrassing. I am standing outside Marks & Spencer's huge London headquarters building, waiting to interview Vittorio Radice - retail guru and head of the company's embryonic home furnishings business - when I realise that I am dressed head-to-toe in M&S product. It's not just the underpants, which are a given. It's the machine-washable linen jacket. It's the white 'easy iron' shirt. It's the socks. It's - Lord save me - the shoes. Only the trousers are from elsewhere and that's because it's a hot day and none of my (five) pairs of M&S jeans were light enough. At best this looks like eagerness to please, but it's much worse than that: this is what I wear every day. Somewhere, somehow, I became man at M&S. Help me. I am only 36.

Now Radice wants to sell me the M&S wardrobe to put all my M&S 'Blue Harbour' clothes in and, meeting him, I am suddenly convinced he could do so. He could probably flog me a black halter-neck dress and a pair of pink mules and I don't think I need those either. There is just something about Radice, a beguiling mix of consumer philosophy and soft Italian affability - he would make a brilliant maître d' - which encourages you to want what he wants you to have.

He says things such as 'shopping is entertainment' or 'product is the manifestation of an emotion' and, although it sounds like marketing-cobblers, particularly in his rich Italian accent, he makes the slogans work. In 1990, aged just 33, he arrived at the then moribund Habitat and turned it around from a company making a £7 million loss to one making a £14m profit. He went to Selfridges and worked the same magic, doubling the value of the company.

Whatever the X-factor it was potent enough to encourage the board of M&S to pay him a golden hello of more than £1m to head up their new home furnishings venture. That market is worth £20 billion a year and M&S has just two per cent of it, compared with 11 per cent of the clothing business (most of that me). The first stand-alone Marks & Spencer Lifestore opens in Gateshead in February.

So, I say, you really do want to sell me the wardrobe? 'Yes of course. And the carpet and the bed. Why not?' And he laughs. Radice laughs a lot. There is an easy, laid-back style to him, uncommon in titans of business. It may be that he has just come back from another one of his famed aromatherapy holidays in Thailand or India, great spiritual retreats where he goes to be massaged, but I suspect he is just like this all the time.

And yet, for all his relaxed affability, I find myself questioning whether the Great British Public really will want to buy their carpets and wardrobes and lights from doughty old M&S. It may have turned its fortunes around from just a few years ago, when the only way for profits was down, but this is a whole new proposition. For example, I don't mind people knowing that I get my ready meals from there or my underpants. Everybody does that. But this furniture thing might be taking it too far. Do I really want to buy my lifestyle from M&S?

'We're not selling a lifestyle,' he says, eyes wide. 'This is just about eclecticism.' Eclecticism is a big word with Radice. He grabs a coffee-table book called Classic Chic by Suzanne Trocme and flicks it open to a picture of a room with chunky sofa, an interesting lamp, a dark carpet. 'This is just a room of a person,' he says. 'We're not saying this is a style. We're providing something to choose from. We all move through life gathering things. We will give you ingredients. How you use those ingredients is up to you.'

This is Radice's big idea, the one for which the company has paid him £1m. The new M&S Home stores won't be divided up into departments: bedding here, sofas there, lighting over the other side. The whole thing will be room sets - called SLEEP or RELAX or COOK - so that the choice of lights and carpets will depend on whether it's a bedroom or living room or a kitchen. It will all be together.

In the middle of the shop will be an entire two-storey house designed by the minimalist architect John Pawson. The catalogue is being designed by Tyler Brulé, the founding editor of the über-hip interiors and lifestyle magazine Wallpaper*. 'We want to make people react,' he says. 'Tell me the last furniture store with a house in the middle?' I mention the Ideal Home Show, but I feel gauche for doing so. 'Most people have rooms in their houses they don't even use,' he says. 'They have to learn if I take this or I take that and put it in the room it will work. It's about making people realise it's their life and they have to do with it what they can.'

To listen to Radice preach the gospel (and he does have a messianic quality) you would think he has been building 'room sets' since he was at nursery, flogging toys to fellow toddlers, but he claims his life has been more varied, 'more eclectic' than that. 'I think my family in Italy are very surprised at what I am doing now,' he says. 'But this is life.'

He grew up by Lake Como in northern Italy, where his parents did run a furniture business, but he says it bored him silly - all that talk over the dinner table of repro television cabinets and scratched table tops that needed returning to the factory. After school he studied agriculture, determined to become a farmer, but he dropped out and drifted for a while. 'This was me,' he says. 'I always lived for the day.' After military service, taking the general's wife shopping, he joined a large American furniture company and eventually became head of world-wide sourcing. He liked flying over Africa to source brass cow bells. He loved searching for 'must have' stuff.

Finally, in 1990, he joined Habitat, first as chief buyer, later as managing director. He thought he'd stay in Britain for a couple of years. This country, he says, is a great place to be in retail. 'Because of the colonial history of Britain, it is open,' he says. 'This is the only country you can eat rocket salad and curry on the same plate.' I say that sounds like a lousy combination. 'So you throw it away and try something else. The thing is the willingness to try. In Italy it's all about conformity. The men, they wear grey trousers, blue jackets and suede shoes. Here it is different.'

At Selfridges he proved it. When he joined as chief executive in 1996, it was a business with a great past and not much future. He propounded his theory of shopping as experience, turning the store into a place you want to be rather than somewhere you go to shop. 'The thing you buy is the souvenir of the experience,' he says. 'People want to be associated with interesting things. The new clothes, the new holidays, the new restaurants.' So he brought in the new. There were 'happenings' in Selfridges. Jerry Hall occupied a window, dressed as Botticelli's Venus.

Pursuing his interest in art - he has two Tracey Emins in his office - he commissioned Sam Taylor-Wood to produce a piece of photographic art to cover the building. He expanded the business, opening new branches in Manchester with another to come in Birmingham. Terence Conran has called him 'the brightest star on the high street' and you can see why.

What he won't do is talk brands or products. They are not what retailing is about, he says. 'For two decades we have been attached to brands,' he says. 'Now we want to live a life that is full.' However, it strikes me that there is a brand at play here and the brand is Vittorio Radice; that this is what M&S purchased when they head-hunted him, as readily as a consumer might buy Ray Bans or Levis. Radice waves the idea away. 'A brand is a suit. It has material, a cut, a lining. I'm not a brand.' And then he says: 'You enter a Conran store and you know what it is immediately. It is something he has been working at for 40 years. I've done four jobs in 20 years.' So maybe it is your philosophy that brands you? Your approach? Again he demurs. 'You can not apply what you learned before in a new situation. It's never the same. If I was just to do the same for M&S as I did for Selfridges what would be the point of the job?'

Eventually, however, he agrees that a good retailer must have a point of view. 'Of course, there is a lot that is unique to me. I'm eclectic in my lifestyle choices. I like contradiction and contrast. Without it where do the ideas come from? I like people who say today I believe one thing, tomorrow I believe something else.' But if someone keeps changing their opinions, if they decide they were wrong the first time, how do we know they're not wrong again? 'Sometimes you get it wrong and that's fine. Seventy per cent right works; 70 per cent is enough.'

I want to know about these lifestyle choices. I want to know what stuff the man-who-sells-stuff buys. What car, for example? 'A Maserati.' Why? 'It's Italian. I also have a Vespa.' Why a Vespa? 'It was a gift.' Which suits? 'I have suits like everybody else.' Bet you don't. You're a wealthy man. 'I have Prada suits.' Why? 'Because I like them.' Is all of this important to you? He shakes his head. 'Except for my wife and my two kids, everything could go. I'm not addicted to stuff.'

This is the great curiosity about Vittorio Radice. His job is to sell objects, to fill homes and, from next year when the Gateshead shop opens, to keep filling homes. And yet he claims to have only a marginal personal interest in objects. When he appeared on Desert Island Discs a few weeks ago the talk was all about those spiritual retreats and driving overland to China; about going 'on a journey without destination' when he retires. Amid the bad Italian pop - and there was quite a lot of that -- there was the sound of Youssou N'Dour and the occasional bit of wistful flute music.

It is a very modern, perhaps even metropolitan, take on the balanced lifestyle. London, where he now lives, has more in common with Milan where he lived when he was younger, than it does with Gateshead. And yet he must now second-guess the tastes and the drives of middle England. Doesn't that worry him? 'Don't judge the customer,' he says, telling me off. 'Don't give them labels. Let them be.'

If he builds it they will come. It is enough, it seems, that he knows what M&S Home Stores won't be. 'We're not after the co-ordinated look,' he says. I ask which co-ordinated look he is referring to and he names two companies but insists I don't quote him but paraphrase him, though the answer is pretty obvious. He doesn't want Marks & Spencer Lifestore to be Ikea or Laura Ashley. Are they the opposition? 'I don't use the word "opposition". I see them as competition.'

And what about my concern that M&S is too old a brand for me? Too middle-aged? Radice says he understands. 'If there is a criticism of M&S, it is that the product is there but we now have to deal with the environment. It has to be fresher, more contemporary.' Hence the John Pawson-designed house in the middle of the Gateshead store. Hence the Tyler Brulé-designed catalogue. This is the new re- engineered M&S and while I don't yet think of myself as the kind of chap who would buy his wardrobe from the company, I don't think I'm in any position to say never. All I can say is, given the quantity of M&S clothing I already own, the wardrobe had better be a big one.