According to French media reports, Sarkozy has asked the former supermodel-turned singer to take a back seat amid a growing chorus of disapproval from his own Right-wing allies about her "luvvy" Left-wing influence.

"(Now) her husband has asked her not to intervene on (political) subjects. And this doesn't bother her," British newspaper 'The Daily Telegraph' quoted a friend of Bruni as telling the '20minutes.fr' website.

In fact, members of Sarkozy's UMP party accuse him of being bewitched by Bruni - recently described by a leading French society magazine as the "new Marie-Antoinette" – and forgetting his own camp.

"Nicolas is subjugated by a model wife who is richer than him and globally known and who constitutes a war trophy as she comes from the Left," said one. "Is it the fault of his wife? ... he no longer likes his electorate," said another.

Another unnamed member of Sarkozy's party even alleged in the magazine that Bruni was responsible for "most of the head of state's woes in this turbulent autumn".

Sarkozy's approval ratings are at their lowest since his 2007 election -- just 39 per cent according to one poll - and he is desperately trying to woo back his core conservative electorate ahead of regional elections next March.

Bruni was seen in public only once in the past month and didn't accompany her husband on a recent state visit.