Francois Hollande and his allies must now seek a revised upper income tax rate for the wealthiest in France, after an initial version was ruled unconstitutional. The tax was among Hollande's key campaign pledges.

French President Francois Hollande did not comment publicly on Saturday after his proposed 75-percent tax rate for the country's top-earners was rejected by France's Constitutional Council. However aides close to the president told the French media that the president was "serene" after the setback.

Prime Minister Jean-Marc Ayrault faced the music in public instead, pledging a revised version of the bill before the end of 2013.

"The government will propose a new system that conforms with the principles laid down by the decision of the Constitutional Council," Ayrault said on Saturday. The council, nicknamed the "wise ones" in France, is comprised of former political, judicial, and civil leaders. It is charged with verifying the legality of draft laws and solving electoral disputes.