The Guardian Council has voted against new legislation that supports plainclothes volunteers acting as morality enforcers, saying it contradicts provisions of the constitution.
The legislation proposes to give legal support to the volunteers, who have been operating mostly under the guidance of Basij forces, and it had been approved by Parliament with a vote of 156 to 23.
The Guardian Council found several problems with the language of the proposed bill and deemed parts of it to be unconstitutional.
The acid attacks on women in Isfahan had triggered earlier criticism of the bill, which would give legal support to volunteers enforcing the Islamic dress code in public.
The Rohani administration had called on Parliament on many occasions to oppose the new bill.