The Council ruled that the planned 75% tax on annual income above one million euros was unfair in the way it would be applied to different households.
The move is a setback for Socialist President Francois Hollande's push to make the rich contribute more to cutting the public deficit.
Prime Minister Jean-Marc Ayrault said the government would redraft the tax-rate proposal to answer the Council's concerns, and resubmit it in a new budget law.
Contextual targeting label:
Local government
