Rachida Dati, the French justice minister, has let it be known she intends to run for mayor of Paris, against Sarkozy's wishes.
The move suggests that Miss Dati, 43, whom Mr Sarkozy demoted by squeezing her out of the cabinet in exchange for a near-certain seat in the European parliament.
She plans to use her post as mayor of the chic 7th arrondissement, as well as her seat on the Paris city council, as a springboard to run for mayor of the capital in 2014.
Last month, the president gave his estranged protégée no choice but to leave her prestigious post as justice minister to take the low-profile position of No 2 on his centre-right UMP party's list for the greater Paris area in the European elections. Although she put a brave face on it, the move was widely seen as an elegant dismissal for the first person of North African descent to hold a top government post.
Once a star of Mr Sarkozy's politically and ethnically diverse cabinet, who according to a newly released book played a pivotal role in patching up relations between the president and his ex-wife Cécilia, she has fallen out of favour in recent months. Presidential support waned due to her clumsy handling of unpopular justice reforms, her inability to retain ministerial aides, and her love of glitz in a time of economic crisis.