BILLIONAIRE BOSS Sir Philip Green has a cunning plan. “At BHS, we’ve got great product, but some of it is a well-kept secret, because we’ve not been great marketers. We need a hook,” he says, leaning back at his desk.

“So I’ll run this past you, Andrew. I’m looking at doing some TV advertising, and I’m thinking, why not do the ad myself, like Victor Kiam? Or Alfred Hitchcock? He appeared in every one of his films, didn’t he? I just need the right script.”

Green shoots a mischievous look. At times like this it is hard to know if he is joking or not. Has he been spending too much time on a Barbados beach with Michael Winner? Or is it all that nightclubbing with Kate Moss, now selling her own line of clothes through his Topshop chain?

“Behave,” he growls. He is off on another jaunt soon, hence the queue outside his office at BHS headquarters in London. Someone saying goodbye, someone getting plans approved, and me.

Green is in and out, shaking hands, cracking jokes, shutting doors, taking calls, his normal routine. He is looking as sleek as a seal: aged 55, tieless, tanned, portly - 6lb heavier than last year because he has been off cigarettes since November - but ebullient, and chewing gum voraciously.

This week he is flying abroad to a health farm, where doubtless he will keep his own schedule. As one of Green’s long-serving secretaries puts it drily, Philip doesn’t do holidays, he just answers the phone from a different place.

And right now he has reasons to be cheerful. Number one, he will shortly be inducted into the World Retail Hall of Fame – a new institution set up to honour “iconic retailers”. Don’t underestimate how chuffed he is.

“Yeah, it’s nice,” he says, beaming with pride. “Voted on by the people who trade next to you, and those in other countries who know your business. It has to be something you respect.”

And that counts because Green is a bundle of insecurities, like most of us, only more so – jokey charm and bullying aggression are just the tip of a mix that drives him to buy, own and run more and more. As owners of BHS and Arcadia, the group that includes Topshop and Miss Selfridge, he and his wife already sit on a fortune of almost £5 billion. Yet still he worries about how the rest of us rate him.

That’s because Green is a gifted retailer, his senses tuned to every nuance of the commercial world, and he is still hands-on in his many businesses. Hence the plans to put himself into ads for BHS.

Vanity? “Nah, I could show you 40 requests for me to do television which I have turned down.” But he likes to control things. He has been promising to find a chief executive to run BHS for some time, yet he can’t get hands-off. Funny, that.

“You’re right, I’ve not found a chief executive yet,” he says in his gravelly baritone. “I am running it part of the time, well, it’s more than a full-time job for part of my life.”

He chortles. But BHS has been struggling of late, and marketing ventures with celebrity chef Gordon Ramsay and designer Kelly Hoppen have not set the world on fire. Green is still wrestling with how to get people into his stores, at a time when costs - rent, rates, fuel - are soaring. Value should be a good proposition, but every high-street retailer now faces tough times.

How tough? “March-April is going to be particularly challenging; an early Easter never bodes well. And last year we had a strong start as it was a hot April, so most retailers were in double figures.” That growth rate will be hard to replicate.

And then? “We are in uncharted waters,” he says, suddenly serious. “If we want to be honest, credit at every level has been far too readily available . . . A lot of people are starting to understand the type of exposure the western world has got.”

So where’s the second reason to be cheerful? Because, as a cash-rich, private owner, Green can sit tight and wait for opportunity. Though for now, he says, he is baffled at the multiples that have been offered in recent retail bids.

“If you have cash or firepower, what’s the definition of cheap?” Money is harder to borrow, savings are tougher to make, and nobody knows where the economy is going. “You would have to be brave to buy into any consumer-facing business, unless you have some different angle or concept.”

Meaning he is not planning a third run at Marks & Spencer? He walked away from his attempt in 2004. He leans over to a waste-paper basket and jettisons his gum.

“The answer is I haven’t bought any shares and am not planning to buy any shares, and if I phoned up this afternoon and offered to pay the same price as before, the biggest worry is they might say yes.”

Peter Cummings, head of corporate banking at HBOS and a longstanding backer, confirms that Green is currently in watchful mode. “Philip never stops learning, and he has a balanced view of risk.”

Anyway, Green has enough to be getting on with. Besides BHS, he has global ambitions for his Topshop and Topman chains. His store’s tie-up with model Moss made many headlines last year. But has it made Topshop money?

He pauses to unwrap some more gum. “Some of the things you do, you do it to develop your brand. And Kate Moss has been fabulously good for Topshop. She is a fashion icon.”

Whom he paid £3m to. “That’s not true.” Moss has certainly raised Topshop’s profile in America. Green is opening a flagship store in New York this autumn. Cost? Up to £12m. Possibility of failure? “Not optional,” he says.

If it works, he has two more New York sites in mind. And he is sniffing round other retailers in America. Then there are talks for franchising in Asia. Topshop rivals Zara and Hennes are in more than 50 markets world-wide. He feels Topshop can do the same.

“But it requires a different skill set for the supply chain and IT, and we need to work on it ahead of the curve.”

Careful international planning, and long focus on operation, is a change of emphasis for Croydon-born Green. He rose up the retail ladder by spotting bargains, reorganising businesses and then selling them.

He says he has always had the retail knack. His dad, who died of a heart attack when Green was 12, worked in electricals. His mum ran launderettes and petrol stations. “It’s in the genes,” he smiles. They sent him to boarding school, which he left at 15 to start selling shoes.

But he has also been a controversial figure. He took stick from the City for the way he ran the quoted retailer Amber Day, whose profits collapsed in the early 1990s. And eyebrows have been raised at his flashy lifestyle and overseas tax status. His businesses are in his wife’s name, and she is a Monaco resident.

It is not in Green’s nature to duck the tough questions - he just fights his corner more loudly. “I am a UK taxpayer,” he says, pounding the chewing gum. “Let me help you for the 25th time . . . I left England in 1998 because I’d had a heart scare in 1995 and wanted to take some time out.”

So when he bought BHS in 2000, and Arcadia in 2002, he struck a deal with his wife that he would come over to run them, but the family would stay in Monaco, because his kids were settled. He now rents a flat in a hotel here, and commutes.

And his companies pay millions of pounds in corporation tax and Vat, he gives millions to charity, his retail academy is already churning out trainees. And the £1 billion and more in dividends Mrs Green has drawn attract the same rate of tax that any foreign investor in a British company would pay.

Don’t get him started. Nor about the press niggling at Third World workers being paid a pittance to make high-street clothes.

“Both my companies take the issues extremely seriously and feel we have in place the right procedures to run a global supply chain.” The government has given him a knighthood for services to retailing, and he doesn’t even hang out with politicians. Enough said.

So what about the sense that he rather enjoys his fame - all those diary pics of him with Kate and Naomi and Elle?

“Oh puh-lease,” he says. But he does love doing his own PR. He will ring me four times after we have met, worrying away about this piece, cracking more jokes. Imagine the grief he would give the crew shooting a TV ad.

Then in comes Sean, his bodyguard, with an Evening Standard, folded open on a diary story about how Green’s wife, Tina, has poached the top chef who cooks for the rich Fiszman family - Danny Fiszman is the Swiss-based diamond dealer who is one of Arsenal’s biggest shareholders.

Green, a Spurs supporter in his youth, reads it avidly, going: “Bollocks . . . bollocks . . . what a load of bollocks.” He looks up and grins. “It wasn’t even the chef, it was the captain of his boat. Now that’s funny.” And he laughs loudly, before clapping me on the back and asking Sean to show me out.

SIR PHILIP GREEN’S WORKING DAY

THE Arcadia and BHS boss wakes at his hotel apartment in London’s Mayfair at 6.30am. “I have a pot of coffee and orange juice, and the previous day’s sales are phoned through,” says Sir Philip Green.

He then attends a business breakfast at 8am, and is driven to one of his two West End offices by 9am: Monday, Wednesday and Friday at BHS, Tuesday and Thursday at Arcadia.

He checks product, examines figures and sees presentations. He rarely lunches out but works through till after 8pm. He then goes out for dinner. “Though I have started cooking for myself,” he says. “It depends.”

VITAL STATISTICS

Born:March 15, 1952

Marital status:married, with two children

School:Carmel College, Berkshire

University:none

First job:working in the warehouse of a shoe wholesaler

Salary package:undisclosed; total wealth £4.9 billion

Homes:London and Monaco Car:black Mercedes S500

Favourite book:‘I can’t remember the last one I read’

Favourite music:George Benson

Favourite film:‘I did see Ocean’s 11, but don’t put that’

Favourite gadget:Nokia 6310 classic mobile phone – he has two and 12 spares to cover for the ones he drops in the sea

Last holiday:Barbados

DOWNTIME

SIR PHILIP GREEN relaxes by watching sport on television. Last weekend he watched Tottenham beat Chelsea. “God likes a fresh winner,” he says of the Spurs victory. He also plays tennis. “I’m hoping to play a bit at the health farm next week.”

He doesn’t spend his money on much, he says, though he will buy expensive wine. “I’ll pay up to £1,000 a bottle.”

His wife, Tina, has just given him a helicopter. “It’s a Eurocopter.” He keeps a model near his desk. He uses the helicopter to fly his family to skiing holidays. Before that his wife gave him a private jet.

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