Ms Dati will be second on the UMP party list in the Paris region
French Justice Minister Rachida Dati, the first politician of North African origin to hold a senior cabinet post in France, is stepping down.
Ms Dati, 43, has attracted criticism for her management style and gossip about her clothes and love life.
She is to run for the ruling UMP party in the June European elections.
President Nicolas Sarkozy did not explain why she was quitting, but made it clear that she could not stay in the cabinet if she became a Euro MP.
While her move has been confirmed by the UMP, Ms Dati herself has not yet commented on it.
She will be number two on the centre-right UMP's list for the Paris region, after Agriculture Minister Michel Barnier. So she is almost certain to get elected to the European Parliament, correspondents say.
Earlier this month she came under fire from women's groups for returning to work just five days after giving birth.
Women in France are guaranteed by law 16 weeks of paid maternity leave, but the French labour code does not apply to ministers like Ms Dati.
A first-time mother, and single, she has kept the father's identity under wraps, telling reporters she had "a complicated private life" and sparking an intense guessing game in the French press.
Ms Dati shot to prominence in 2007, as a symbol of ethnic diversity in President Sarkozy's new administration. She had served as his campaign spokeswoman.
She was born in 1965 to a Moroccan mason father and an Algerian mother, one of 12 children raised in a tower block in a deprived neighbourhood.
At the age of 16, she started working as a carer in a private clinic.
She later gained degrees in both economics and law, spending two years at the prestigious National College of Magistrates.
Her role as justice minister has been controversial, with magistrates and lawyers accusing her of pushing through reforms without sufficient consultation. Several of her justice ministry aides have resigned.
Pictures of her wearing designer jewellery and dresses have appeared repeatedly in magazines, giving ammunition to critics who point to the economic hardship endured by many French people today.