'We are going to win'

The lift rocks alarmingly and your ears pop as you reach the 50th floor office at Canary Wharf of Barbara Cassani, the American businesswoman who started the budget airline Go with a mobile phone and a lot of chutzpah.

To her left, through the vast picture windows, she can see the Lea Valley laid out like the credits for EastEnders. There, if she has her way, the Olympics will take place in a frenzy of activity in 2012.

For the moment, though, things are lower key. The vast office is utterly bare except for a sea of grey carpet and a little, lonely cluster of desks at the far end. Ten people perch round them staring at computer screens. It seems the only colour in the whole place is the bright poppy-red of Cassani's dress.

A little slip of a thing, with thin arms, blue-green eyes that are defensive and humorous by turns and a schoolmarm cool if you ask the wrong question, Cassani is the person with the dubious responsibility of leading London's bid for the 2012 Olympic games. She is seven weeks into the job and knows it will not be easy.

"We're being watched from all sides. It's a very stressful thing we're trying to do," she admits in her well-modulated East Coast accent. "The Olympics are a public good, and everyone feels they own a little bit of it. But I've spoken to people who have done other bids. They all say, 'Oh, you're in the confusion stage, don't worry'. I'm like, 'When do I get out of the confusion stage?' "

Cassani is the woman who set up Go in six months from scratch for British Airways, saw its value leap from £110 million to £374 million in a year, and pocketed a reported £9.5 million when it was sold to EasyJet. She has a reputation as a Superwoman, a loudmouthed American who exclaims "Holy cow", can be hard as nails and is a legend in the business world. Her mother Noreen says she's exhausting to be around even when she's relaxed. But the 42-year-old, who juggles two children with an English banker husband and the odd 10K run, is actually, in the flesh, disarmingly feminine and self-deprecating.

Tiny diamond cubes glint in her ears and her lipstick is the precise red of her dress. She hates the superwoman tag. "I never planned my career," she protests. "I never had a game plan. I'm only aware of being successful when people ask me about it. I think some successful women are very man-like.

'But I try not to make generalisations. I've never sat down and analysed myself. I've met people who say, 'I want to do so and so in 10 years.' I'm like, 'Really?' I mean, when I got involved in Go I had no idea where it would go. Absolutely none! I just took it a step at a time." She launched Go five years ago when Bob Ayling, BA's then chief executive, decided he wanted someone to set up a low-cost alternative to easyJet, Ryanair and the now defunct Debonair. He turned to Cassani. She was handed £25 million to launch it. There would be no more funding: Go would stand or fall on her decisions.

"I looked at what the other airlines had done," she has said, "took the best of everything, then created a brand that was inclusive but was also about the future."

But if that was a triumph, there are many who think her new job is a poisoned chalice. Cassani admits herself that the difference is that she has to do it in the full glare of the public eye. However, she insists that she can do it.

"I feel very positive about it. I wouldn't have taken the job if I thought, 'Oh, let's just have a go,' " she says. So what chance does she give London of getting the Olympics? Sixty-forty? Fiftyfifty?

"Oh, 100 per cent," she declares, her earrings flashing with determination. Then she ruins the effect rather by adding: "You have to say that. You have to come in every day and say, 'We're going to win'. Not in an arrogant way, but the way an athlete would prepare for the Olympics."

How would she feel if she lost? " Devastated. Absolutely devastated. Losing stinks."

Frankly, though, it seems as if Cassani has never lost at anything, with her rich banker husband, children of 10 and seven who lap up Harry Potter, and glittering CV. Born in 1960 to an Irish-American mother and Italian-American salesman father, she worked her way through Mount Holyoke College in New England, where she did her degree.

"I was lucky that my parents could put me through university but the deal was I had to pay my own expenses, for books and spending money," she says. "I was the person at the microphone in Burger King. It was grim but it was money. Though in retrospect it helped me to put myself in the shoes of people I later employed or worked with."

She went on to do a Masters in international relations at Princeton, where she met her husband, Guy Davis (they married when she was 25). Her first job was in management consultancy and then she had a decade at British Airways, which culminated with the massive success of Go.

"But to me I lost at Go," she contradicts. "It was my baby. And I fought and fought and fought to keep it. But ultimately it was owned by a venture capital group, and they sold it and it disappeared. It was so sad."

Her eyes darken at the memory of the takeover of Go by its brash rivals easyJet in July last year - she felt let down, she said at the time, and she felt that the venture capitalists of 3i could have doubled their money had they been patient and honoured their promise to give her three years in the job.

"It's funny," she goes on. "I was talking to someone the other day who was with me when we started it up, and I said: 'You know, if we'd known how hard it was going to be, we'd have probably been frozen [and not able to do it].' And I think there's a certain beauty to innocence. The people who I have huge admiration for are the people who do it again and again. To know what you're getting into - and do it. They're the crazy ones."

So is she crazy, doing it again? "No, this is different. I'm chairman, not chief executive." She jerks her head at the next-door office, where her chief executive can be seen settling nervously into his first day - he hasn't got a computer yet. "He gets to do the crazy work. Plus this is about giving something back."

Cassani admitted last year that the period before the takeover of Go was "a very difficult time for me and my family; we were under great strain"; and after the sale she felt bereft. Her husband, a former triathlete, had taken a career break from investment banking and they reportedly spoke of returning to America. (Though Cassani is anxious to stress how British she feels and how content she and her husband are living in Barnes - "London's the only city I could live in; it's a fantastic place, so beautiful".)

She has helped buy a pub in Barnes called The Bridge, which was turned into a popular and sophisticated eaterie, bought an eventing horse called Rongotai (she adores riding and rode competitively as a teenager). Then they went off on a long holiday in Australia, where she began working on a book about her time at Go, an exercise which says was "cathartic. In fact, one of my friends said, 'This is better than therapy'."

Didn't the money cushion the blow? She shakes her head. "I don't mean to sound ungrateful. But I'm not a 'huge pile of money' person. My view is you need to pay your bills every month and be comfortable." After those months in the wilderness, she is on to her next challenge. London has begun work on its Olympic bid way behind its main rivals in New York, Paris, Madrid and Rio. But she says that doesn't matter. Her battle plan is to convince the public that her team can put together a good bid and to create a proposal that will meet the needs of both the International Olympic Committee and the Lea Valley and London as a whole.

"I guess I have a 'get on with it' philosophy of life," she observes. "I like to accomplish things and then look back and say, 'That was a good year'. I like feeling I've made a difference. Which is why I find people who are frightened to change or resistant to new things so challenging. I'm like: 'You're not going to die if you fail!' I think that's been one of the issues with the bid. There's a fear of failure that is evident in the UK and we need to get over it in order to do well."

And what about her husband? Does he think she's done well? She gives a wry smile. "Oh, I don't know. I think we're each other's supporter. He just won a whole load of gold medals at a county level competition at the weekend for swimming. So I think we're each supportive of each other in our own worlds." Gold medals? Now that could be a very good sign indeed when it comes to the prize of the Olympic Games.