It was Ms Dati who managed to upstage Carla Bruni, the glamorous and controversial new first lady, at a reception last week for visiting Israeli President Shimon Peres.

Bruni was supposed to have been the focus at her first official dinner at the Elysee Palace, but it was Ms Dati, in a revealing satin gown split to mid-thigh, that drew gasps.

A poll on Ms Dati's image conducted by internet news site 20minutes.fr found supporters of either sex were rare. One respondent scoffed at her 'strutting about', while another asserted: 'Singers, celebrities, I can understand that they always need to sell themselves to the public ... but a political figure, that leaves me stunned.'

Yet Eric Fassin, a sociologist and researcher at the School for Advanced Studies in the Social Sciences in Paris, sees Ms Dati's fashion choices as part of a public coming-out as one of the 'visible minorities' in French political life.

The daughter of a Moroccan bricklayer, Ms Dati emerged as the first Muslim woman of North African origin to hold such a key post in France and a heroine of the immigrant class.

Dubbed 'The face of changing France' by Paris Match, Ms Dati has nevertheless come under fire from judges and former ministers for flaunting her wealth and playing up a sexy persona, earning her the nickname the 'Barbie Doll minister'.

'It's not by accident if women politicians or Muslim politicians put themselves on a stage so visible, hypervisable - just as Rachida Dati is doing ... it explains the concern for appearance,' Mr Fassin said. 'It's to make her political presence very obvious while obscuring the fact that she was not actually voted into parliament. The 'look' therefore has a political sense.'

Ms Dati's biographer, Lionel Cottu, said any criticism would make little difference to the minister, whom he described as being 'glamorous, determined and impetuous'.

'Attacks only serve to boost her,' he said. 'She is gutsy in everything she does.' As he wrote in his book: 'Dare, always dare. It's her leitmotif.'

Having analysed Ms Dati's style for Gala Magazine, fashion critic Justine Boivin described her as 'a diva of the Republic' practising 'politics in high heels' with a style 'more sartorial than political'.

'Because she is aware of having an image of being a very iron-fisted female politician, she always seeks the loveliest velvet glove to mask her toughness and her renowned moodiness ... She has expressed outrage at the voyeuristic media attention on her glamour image yet then proceeds to spends hours in the fitting rooms of Dior and other fashion houses.'

Accusations that she has forgotten her working-class roots have emerged in parallel with the controversy about her fashion choices. She is a regular at gala events and boasts friendships with fashion house directors and leading designers.

Political writer Jean-Pierre Bedei, writing in La Depeche du Midi, said the matter had reached the point where 'one can classify the minister as much in the category 'people' as 'political''.

Mr Sarkozy, however, has shown deep loyalty.

Ms Dati has never sought to argue with critics about her love for haute couture, sticking to what she told Paris Match: 'Ever since I was little I have had a taste for being well dressed. It's a question of showing respect to others.'