MICHELLE Mone was at a dinner dance when she decided she'd had enough of under-wired, cleavage enhancing bras. "I was sick of feeling uncomfortable," she says.

It led her to thinking about how she could find a bra that was natural and moved with her, as well as having the all important uplift.

Having been made redundant as sales and marketing manager for Labatts Brewers in Glasgow, she used the money to fund the launch of her own company, MJM International, with her husband Michael.

Four years later, Michelle, who left school at 15 with no qualifications, has a company with a turnover of £10m (compared to £300,000 in 1999), a staff of 550 - and the fastest growing bra in the world.

Ultimo is her invention, and it's taken the lingerie industry by storm. It was launched at Selfridges in London last year and is now available at the Queen's corsetieres Rigby & Peller and, most recently, Saks Fifth Avenue in New York. It's been so successful that the company had to invest in a new head office with showroom, offices and distribution facilities, ten times the size of the old factory. Meanwhile, Michelle has been a dinner guest of the Prime Minister, knows the Prince of Wales well and was next to football star Ryan Giggs in the Sunday Times Rich List - and she's still just 28.

In Florida in April, she won the coveted World Young Business Achiever, beating off entrepreneurs from 14 countries. She's also managed to fit in having two more babies - with her one-year-old she went into labour at work and was back two days after giving birth.

But while, one day, she will undoubtedly be a very wealthy woman, the last few years haven't been easy as she took on the might of the lingerie business. The David and Goliath battle continues to rage today.

Ultimo was the original gel-filled bra and has spawned numerous copies, but in order to stay one step ahead of the big boys Michelle can't afford to relax for a second.

The secret of Ultimo lies in the liquid silicon gel cushions sewn into the bra that act like a pair of hands, gripping the side of the breasts and holding them in place but also allowing the bra to move with the woman wearing it.

The substance was developed by a German scientist following Michelle's instructions about what she wanted the bra to do.

Not surprisingly, other manufacturers jumped on the idea of the cleavage enhancing bra that was comfortable too. As well as gel 'outplants', others have come up with water, oil and now Wonderbra has developed the air-filled Pump Action bra.

Feisty blonde Michelle isn't backwards in coming forwards about what she thinks. "Other companies are riding on the back of Ultimo and trying to rip off the idea. I tried water and oil years ago and they just don't work. Because my design is patented and they can't use it, they have to try out gimmicky things.

"Women can tell the difference when they try the products. I really feel that we've got the best, no one is going to touch us. Our bra makes your shape better, it's comfortable whereas under-wired bras aren't. You could even go to bed in it."

Her rivals respond by saying that, while Michelle originated the gel-filled bra, she can't keep up with the competition on price - Ultimo starts at £29, £2 more than the latest Wonderbra.

Michelle may have the last laugh, however, when she reveals that she's signed the most "famous woman in the world" for Ultimo's latest advertising campaign. She was keeping mum about who it is at the Harrogate Lingerie and Swimwear Exhibition last week, but, by way of a clue, the mystery woman's fee was going to run into millions so it was cheaper to let her join the company.

Also at Harrogate, MJM International unveiled its latest products - the Ultimo Plunge bra, Ultimo Swimwear and Ultimo Perfectline Seamfree underwear.

Next year the Ultimo bra will be available in bigger sizes, but before then Michelle has more work to do as an ambassador for the Prince's Trust and a BBC documentary based on a year in her life.

Consequently, some people were surprised that she attended the Harrogate exhibition in person. Michelle is quite clear about why she was there.

"You can't be complacent in this industry, not for a second. Everyone warned me that the big boys would kill me but I've managed to stay ahead.

"If I'm not where the customers are, meeting them and talking to them, then there's no point."