In the Dragons' Den television series, several very rich men like to get their wallets out in public and wave them around. Size matters in such circles.

While contestants compete for investment in their (often loony) ventures, the stars of the show compete with each other. Who's the smartest, the coolest, the richest? Who's got the biggest wallet to wave? Duncan Bannatyne reckons it's him. "We respect each other, though there are big egos there," he says. "But I'm worth more than Peter Jones and Theo Paphitis [the other two long-running dragons] put together.

"I wouldn't say that publicly, but a journalist might," he adds mischievously. "You might say it, but I wouldn't.

"The other thing is, Peter thinks he's the best looking of the Dragons, but I know it's me."

He laughs with a glint in his eye. Bannatyne's a born entrepreneur, always looking for angle, always playing the deal. He's joking, sort of.

Judged by the forthcoming Sunday Times Rich List, to be published next Sunday, Bannatyne has a point, at least on his wealth. He's now estimated to be worth £310m, making him the 267th richest person in the country. Pretty cool for a poor boy who made his first stash selling ice-creams.

Jones and Paphitis limp in as relative paupers on £157m and £135m respectively. Don't weep too much. Remember that ordinary wage slaves just want to keep up with the Joneses, but the Peter Joneses of this world want to keep up with the Bannatynes.

As for Paphitis, he's really not happy, according to Bannatyne. "Theo hates me," he says. "He hates everyone. He has a miserable life." He's joking, sort of.

For the super-rich, of course, making money is not the sole pre-occupation. No really, it's not, avers Bannatyne, who says straight-faced: "The money's only important if you haven't got any." Once you're loaded enough not to worry about your next villa, the psyche tunes in elsewhere as well: fame, reputation, peer comparison, and the latest badge of honour for the rich, giving something back. This week Bannatyne is presenting an ITV programme on the rich that has philanthropy as a key theme. It's a tricky subject for the cynical British, who still tend to view philanthropy as a sticking plaster on the sore of inequality. But Bannatyne has the fervour of a convert. "The programme is a sort of television version of the Rich List," he says. "But instead of talking to people about 'how big is your yacht', I'm asking 'how can you help the under-privileged? what do you do?'. I believe that giving the money you make away is the best reason for making it in the first place."

The trouble is, he says, we still find it hard to give altruism due recognition. Bannatyne thinks it's time attitudes changed.

"If we [the rich] help someone and we tell a newspaper about it, somebody says it's a publicity stunt, it's a tax write-off — nobody ever says 'oh well done'. So some entrepreneurs say 'I'll do my giving quietly'. But there's a feeling at the moment that we should talk about it because it will encourage more entrepreneurs to give money away." The late Anita Roddick is one of the entrepreneurs who led the way. She said she would give away her wealth and she did: last week it emerged that Roddick, who died last year, gave the bulk of her £51m fortune to her charitable foundation and left an estate of just £665,000.

In the programme Bannatyne meets other entrepreneurs who are also pushing back the boundaries. There's Lord Philip Harris, carpet fitter to the nation, who donates 20% of his income to good causes; Sir Tom Hunter, the Scottish entrepreneur who has pledged to give away £1 billion in his lifetime; Sir Michael Spencer, whose City firm Icap devotes a day's revenue every year to charity; and Felix Dennis, the maverick publisher who plans to use much of his wealth to create a forest. While Dennis is something of a menace to himself — he recently told one interviewer that he had killed a man before retracting the claim as "hogwash" — his forest will be a lasting benefit for the public, says Bannatyne.