As Nicolas Sarkozy strives in his re-election campaign to shed a flashy image and rebrand himself as president of the people, France's glamorous first lady Carla Bruni seems to be undergoing a reverse makeover to appear a little more ordinary.

A head-turning former supermodel and singer who posed nude and dated rock stars before her romance with the newly elected Sarkozy in 2007, Bruni dazzled in designer garb and stylish hairdos in her early years as the president's third wife.

Appearing for the first time at a campaign rally on Sunday, the 44-year-old looked deliberately understated in a dour jacket and trousers with minimal make-up and hair worn loose.

Even more startling was the Italian-born heiress's appearance on the cover of a lowbrow TV listings magazine last week, curled up on a sofa in a dowdy grey sweater, comfy trousers and socks, raving about the shows she likes to watch.

A world away from a glossy 2008 photoshoot for Vanity Fair, in which she posed on the roof of the presidential palace in a strapless blood-red ballgown, Bruni played first housewife as she talked about watching reality shows while cuddling her four-month-old baby, Giulia.

She appeared the same day in 20 Minutes, a free daily paper handed out in underground stations. Wearing a chunky brown cardigan, no make-up and her hair ungroomed, Bruni said she would be 100 per cent at Sarkozy's side in the campaign.

Her new look comes as Sarkozy is battling to overturn an image set early in his term of being too flashy and too drawn to the company of rich businessmen, in contrast to past presidents who had simpler tastes more in tune with rural France.

Paparazzi followed every step of his whirlwind courtship of the eye-catching Bruni in late 2007, horrifying many in France.

"The celebrity couple image did a lot of damage by upsetting his traditional conservative base," said University of Lorraine political scientist Arnaud Mercier. "Sarkozy wants to correct that by portraying them as ordinary, but the 'bling-bling' image is so firmly rooted that people may not be convinced."

Opinion polls show two-thirds of respondents have a negative opinion of Sarkozy and he lags Socialist Francois Hollande -- a self-styled "Mr. Normal" who used to ride a scooter to work -- in polls for the two-round election on 22 April and 6 May.

The conservative Sarkozy, who is also criticised for a brash way of speaking that jars with France's intellectual elite, vowed in Marseille that he would stand for "the people, not the elite", as he fights for a second term.

Many have not forgiven him for celebrating his 2007 election win with wealthy supporters in an exclusive Paris restaurant, Fouquet's, holidaying on a businessman friend's luxury yacht and starting by easing taxes on the rich.

"The challenge ... is to make people believe that despite Fouquet's, the yacht, the billionaire friends and the cut in wealth taxes, he is a man of the people," the left-leaning daily Liberation sniffed in an editorial.

In the second big speech of his campaign, Sarkozy accused Hollande of lacking the courage to be honest about or tackle the economic risks facing France. Hollande retorted that he would not be dragged into a schoolboy-style spat.

Sarkozy is pitting his energetic, aggressive style against the affable but bland Hollande in a contest to strike a chord with everyday voters. His catwalk-star wife is reinventing herself with the same determination as a supportive spouse.

Far from spending their evenings hob-nobbing with the elite, Bruni told TV Magazine the first couple often relax in front of the television. She raved about Love is in the Meadow, a reality dating show with a mass audience that matches city-based singletons with lonely farmers, but said Sarkozy prefers sports.

"He watches all the sport channels," said Bruni, who in 2008 told Vanity Fair she would model herself on Jackie Kennedy. "He's a big fan and he got me into watching the Tour de France."