He was unhappy that the party did not give him ticket for the Gandhinagar South seat. On Dec 2, Amin had asked his supporters to desist from campaigning for Congress candidates.
A day earlier, those loyal to Amin had sent their resignations to state Congress President Arjun Modhwadia. Though the party tried to placate the powerful leader by reportedly offering him the chance to shift to Delhi, Amin refused to budge.
Today, Amin resigned from all the posts which he held in the party. He quit within hours of the party releasing its election manifesto.
The BJP is expected to benefit from the discontent in the Congress ranks.