It takes a plane, a train and a car to get to Sir Richard Branson's new Alpine hideaway near Verbier in Switzerland. He has the smartest chalet in the chicest Swiss resort, of course. There is a hot tub on the terrace, a swimming pool in the basement and a ski piste outside the door. But Britain's best-known entrepreneur pads down the steps to meet us in his socks. He is wearing a faded blue shirt - no tie. There are no flunkies in sight.

This slightly shambolic character is more than a businessman, he is a brand. And he is no longer content with running companies; these days he wants to influence the world.

The day before our meeting he has been to No 10 for a meeting of Gordon Brown's Business Council. He is about to fly to Johannesburg to gather his group of “elders”, including Nelson Mandela, Desmond Tutu and Kofi Annan, to try to solve the problems in Zimbabwe. Recently, he invited Tony Blair to his Caribbean Island, Necker, to discuss climate change. Having been thwarted in his attempt to take over Northern Rock, he now wants to buy into the NHS with Virgin polyclinics. Next he plans to conquer space, with a Virgin rocket. “I love a challenge. I love learning about things I know nothing about,” he says. “I hate saying no. I'm known as Dr Yes.”

He has just agreed to fly five rare baby gorillas from a zoo in Britain to Africa, for release into the wild. His hobby is rescuing over-emotional supermodels. “I'll always help a damsel in distress,” he says of Kate Moss. Although he founded the record company that signed the Sex Pistols, he is an unashamed old fogey. “I'm more Radio 4 than Radio 1 now, I'm afraid. I can receive e-mails on my BlackBerry but I need the girls to help me send them. And I don't know my PIN number. I carry tip money rather than cash.” These days, he says, he prefers “The Queen to Queen”.

The Establishment finds his celebrity love-ins and his daredevil stunts irritating. The City is suspicious of his complicated finances. But politicians want him on their side because they know that he has the populist touch. He is a trendspotter rather than a trendsetter. Although he has never endorsed a political party, he is seen at Westminster as a weather vane of public opinion.

Sir Richard moved seamlessly from Mr Blair (who put him forward for his knighthood) to Mr Brown. Now he is clearly intrigued by David Cameron, whom he met recently. “Politics is about individuals,” he says. “I liked David Cameron.” There is a pause before he adds: “I like Gordon Brown too.” He insists that he has nothing against the Prime Minister - “he's a capable politician” - but when he defines the qualities needed in a leader he seems to be listing all the things that Mr Brown is not and that Mr Cameron is.

“You've got to be good with people, a great motivator, a good listener, someone who can inspire people... It certainly helps if you can be relaxed in front of the television cameras.” Delegation, he believes, is key. “The principal job of a leader is to find good people so their own desk is clear and they can deal with crises and have time to think about new ideas.”

Luck is crucial: “There is a very thin dividing line between success or failure, and there were some occasions when I came very close to being on the wrong side of that dividing line.” But he thinks that Mr Brown has also made mistakes. “Timing is everything in politics but there have definitely been a few self-inflicted wounds.” The on-off election and the 10p tax row were two. On Northern Rock, “they bottled it”. Does he miss Mr Blair? “Let's talk about the airline industry,” he replies.

Sir Richard doesn't have any qualms about discussing what he thinks is turning into global economic meltdown. “The financial state of the world is just about the worst I've ever known it. It's getting perilously close to being worse than the 1990s. You have the perfect storm - you've not only got the banking crisis and the housing crisis, you've got the soaring fuel prices as well.” There will, he believes, be “some spectacular casualties” in the airline industry over the next 12 months. “One of the big American carriers will almost definitely go.” In this country, he hopes to snap up bmi.

The Prime Minister insists that Britain is best placed to weather the storm - but in Sir Richard's view this is one of the most vulnerable countries in the world. “Because we're so reliant on banking, I think we're in a worse situation than most other countries except perhaps America.”

He is worried that the tax regime introduced by Mr Brown could undermine competitiveness. “Obviously what Britain doesn't want to have happen is to see a lot of companies moving their headquarters overseas, I think there is a risk of that.”

The Government's levy on non-doms was a mistake. “Britain is better off having these people here than frightening them off and having them go and live elsewhere.” Changing the capital gains tax system was also an error. “There have been a couple of decisions which I suspect the Government regrets making. If you tax people more you are not necessarily going to get more tax - they will leave.”

The creaking infrastructure is bad for business too, he says. Sir Richard wants a new high-speed rail link up the East Coast mainline and a third runway at Heathrow. “As a country we have been very slow in putting money into infratructure.” Terminal 5 was a fiasco. “It's been embarrassing to be British looking at foreigners queuing up to come into the country. I certainly think that BAA should be broken up. Each individual terminal at Heathrow should be privatised so they can compete against each other. BAA just creams off more and more every year.”

In general he thinks that the private sector is more efficient than the public one. His daughter Holly, who has just qualified as a doctor, is going to help him to bid to run the giant GP polyclinics that are being introduced as the next stage of NHS reform. “Aspects of the NHS could be better run, but we've got to be sure we're going to get a return on the money.”

Businessmen should not, however, just be raking in profits. They must put something back into society “not just get bigger yachts”, Sir Richard says. “I certainly don't want my kids to have tens of millions of pounds sitting in a bank account. If they get involved in running the companies the ownership may end up with them but they have to earn it. They have to realise that the wealth is not there for them, it's to create new jobs and tackle social problems in the world.”

Climate change is in his view the “biggest crisis” facing the world. He is spending millions trying to work out how to run his planes on algae. “There are fuels like sugar-based ethanol that don't eat into the food supply. I've been urging the Government to lift all importation duty on that.”

The group of “elders” he set up with Peter Gabriel is using its “moral authority” behind the scenes in Zimbabwe. The aim is to try to persuade Robert Mugabe to stand down. “There are elders - Kofi Annan, Archbishop Tutu, President Carter, Nelson Mandela, who are willing and ready to get on a plane to go into Zimbabwe at any time that they can get an invite,” he says. “There's no point going unless Mugabe and the military around him are willing to invite them.”

Sir Richard is becoming more and more political. But he thinks he can have more influence in business than in Parliament. “In my 30 years as a businessman I've been to Chequers and seen seven prime ministers for dinner - they don't exactly have a very long career. I hope to have another 30 years of what I'm doing.”

Quickfire questions

Rolling Stones or Beatles?
Rolling Stones

London or New York?
London

Train or plane?
Train

Doctor Who or Captain Kirk?
Captain Kirk

Queen or the Queen?
The Queen

Hogwarts or St Trinians?
I prefer girls, so St Trinians

CV

Born
July 18, 1950, to a lawyer and an airline stewardess

Educated
Stowe School. Branson is dyslexic and left aged 15. After leaving school he set up a national magazine, Student. A year later, aged 17, he established a student advisory service

1972 Set up Virgin Records. The first record it released was Mike Oldfield’s Tubular Bells, which sold more than five million. Branson later signed up the Sex Pistols

1984 Formed Virgin Atlantic, now Britain’s second largest long-haul international airline

1992 Sold Virgin music label to EMI in to fund airline. Since then, Branson’s empire has expanded to include trains, mobile phones and health clubs. He wants to move into polyclinics

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