Carla la Magnifique? Anne Penketh says 'Oui'

The French President's wife has left Britain smitten, with her sparkling display of timeless elegance

The City of London Corporation is a stickler for tradition at its formal banquets in the medieval Guildhall. When the French President and his new wife arrived for a white-tie dinner on Thursday evening, they were treated to a trumpet fanfare by the Blues and Royals and had to join a procession round the dining hall accompanied by a slow hand clap from the standing guests.

And then I caught sight of Carla Bruni-Sarkozy's bottom. I can't remember whether she was walking in front of her husband or behind him as they passed by my table. But as Carla glided by, I was treated to the full-frontal as she flashed that perfect smile that I had seen so many times over the past two days since she arrived with Nicolas Sarkozy on his state visit to Britain. She was wrapped in a wine-coloured sleeveless gown that clung to her buttocks, emphasising her curves. She did not strut like the supermodel she once was, she glided, ramrod straight along the carpet. She had poise, elegance and class. Never mind the fact that she has the confidence to marry a man smaller than herself. And I realised that I had fallen for the Carla charm that had knocked the French President off his feet.

My fascination with Carla began on Wednesday when she emerged at Heathrow. A 15-year-old photograph of her naked body had been splashed all over the tabloids. How was she going to react? As she stepped out wearing her demure grey below-the-knee Dior outfit, I knew this state visit was going to be all about Carla's revenge. And how. This was no Raisa Gorbachev, another wife of a president who caused a stir when she travelled abroad. As countless others have written, this is a woman with star quality of the likes of Diana, Princess of Wales, Jackie Kennedy and Princess Grace. I am mesmerised. I can't get enough of her.

Of course I was vaguely aware of Carla's previous incarnations as the woman who stole the hearts of Mick Jagger and Eric Clapton; the serial man-snatcher who seduced a French philosopher and then went off with his son, with whom she had a baby. More recently, I listened to a lilting song in a friend's car. "What's that?" I said, as a gentle voice sang wistfully "quelqu'un m'a dit... que tu m'aimais encore". "Oh that's Carla Bruni, you know, the model. It's a cult hit in France." I went straight out to buy the CD. The next I heard of her, she was being wooed in public by the French President.

He's smitten. You should have seen him on Thursday when a French reporter asked him whether he felt overshadowed by all the attention being lavished on his wife. He almost seemed grateful for the question, even though he upbraided the journalist. "So much has been said and so much has been written that I am proud that people have seen her for what she really is, and that there is a sense of justice," he retorted. "Let me tell you, I have been deeply moved by what has been said over the last two days. I think she has been an honour to our country, not simply because of the way she looks, but beyond that everyone understands that this is a woman who has belief, sensitivity and humanity." You see, for Sarkozy, too, this was all about revenge.

But there is another aspect to the Carla phenomenon. She is not just a pretty face. She is a most astute businesswoman from a gilded Italian background who has already taken advantage of her tremendous pulling power to increase her own worth.

When she was still the President's girlfriend, she was in ads on French television vaunting the merits of the Lancia Musa – Italian for Muse, geddit? The magazine version which appeared after their marriage was a subliminal masterpiece, showing parts of her face and body and with a headline proclaiming "Five-Year Guarantee" – the length of the presidential term. Her CD Quelqu'un m'a dit has sold more than two million copies, and there's a new one just out.

The person I feel sorry for is Sarkozy. He has fallen for one of the world's most glamorous women who is certain to ditch him, sooner rather than later, when she gets bored with lunching at the Elysée Palace with the wives of presidents of small African countries, even though she now claims to be "the first lady until the end of my husband's term of office and his wife until death". She has rebranded herself as a singer and now as first lady. I'm sure that Carla, and her bottom, have not finished with us yet.