The Sarkozys' marriage has often been the subject of speculation in the French press, breaking media taboos on the reporting of politicians' private lives in France.

The couple separated briefly in 2005, when Ms. Sarkozy had an affair with an advertising executive. Although they got back together in a blaze of publicity at the start of last year, she played no public part in her husband's election campaign.

She did not vote for him at the second-round ballot, and has accompanied him in an official capacity only three times - the last of them in July - since he won the presidency in May.

Rumors were rife when Ms. Sarkozy failed to join her husband for lunch with the U.S. president, George Bush, in the U.S. in August.

The French leader and his wife were spending their holidays in the area, but she cancelled, claiming a severe sore throat. She was later seen shopping with friends.

Asked about her possible role as the president's wife two years ago, she said: "I don't see myself as a first lady. It bores me. I'm not politically correct."

Thursday's announcement came as Sarkozy faced the challenges of a crippling two-day public transport strike in protest at his pension reform plans and an European Union summit in Lisbon on the new reform treaty.