Fancy a date? Geri Halliwell picks Edward Spencer from the crowd

Bridget's other love - the strong silent Mark Darcy - is played by Colin Firth, TV's Mr Darcy in Pride and Prejudice.

Bridget Jones's Diary began as a spoof column by Fielding in The Independent, on which she then based a novel which was hailed as a "sign of the times" book when it was published in 1997.

The book went on to sell more than 4m copies worldwide, with 1.5m sales in the UK alone.

Fans of the book, including the singer Geri Halliwell, flocked to the premiere.

The former Spice Girl, in a daring backless dress, made one young fan's night by inviting him to join her for the screening.

Her more usual escort Robbie Williams was absent - spotted drinking in a West London pub after playing football with friends Ant and Dec, EastEnders star Michael Greco and Jonathan Wilkes.

Halliwell - who provides the song It's Raining Men for the soundtrack - said she was a big fan of the Bridget Jones books.

I like drunk girls very much

Hugh Grant

"I completely identify with the girl. I have read both books," she said.

Bridget is a single woman aged 32 whose main preoccupations are her angst-filled relationships (or lack of them), the calorie count of her frequent glasses of Chardonnay and her alarming nicotine habit.

Though it was intended as parody, since its publication countless women have come forward to say how much they identified with the character.

Grant said he found women like Bridget appealing.

"I like disaster girls," he said.

"I like girls that don't care about themselves too much. I like natural, un-done-up English sexiness."

Weight loss

However the news that a svelte Texan actress would play the decidedly cuddly Jones was greeted with snorts of derision by those who know Bridget.

But Zellweger went on a weight-gaining diet and worked for a time as a temp at Fielding's publishers in London in order to play the role convincingly.

She showed off how she had regained her figure in a revealing black crocheted dress.

But she said she had enjoyed the liberation of not watching what she ate prior to filming.

The book that started it all - a 90s publishing phenomenon

"I could eat an extra chocolate chip cookie and this time it's good for the soul."

The choice of Zellweger to play an English woman also raised a few eyebrows.

But the film's director Sharon Maguire said Zellweger's accent justified her choice.

"No-one was more surprised than me to cast an American, but she was just right for the role. I don't think I made the wrong decision."

It is the first major film by Maguire, who is a friend of Fielding's and supposedly the inspiration for Bridget's best friend Shazza in the book.

Richard Curtis - the man responsible for both Notting Hill and Four Weddings and a Funeral - wrote the script in collaboration with Fielding, who is also a friend.

The film opens in cinemas across the UK on 13 April.