Thursday’s Constitutional Court ruling found that the amendment adopted by the assembly on June 29 was “contrary to the Constitution”.
The proposed changes included a provision prohibiting a sitting president from serving as leader of a political party.
The push for constitutional reform has been driven by the ruling Pastef party, led by parliament speaker and former Prime Minister Ousmane Sonko.
Critics of the proposed reforms have said the amendment was an attempted power grab by Sonko, whom Faye dismissed as head of government in May.
The Constitutional Court said Faye had asked it to review lawmakers’ procedures in order to detect violations that would invalidate the reform.
The political upheaval related to the split between former allies Faye and Sonko could complicate Senegal’s efforts to resolve a crisis stemming from the disclosure of misreported debt in 2024.
Sonko said on X he respected the court’s decision.