The complainant alleged that the act reflected caste-based prejudice, social contempt and a sense of hatred and inferiority towards a member of the Scheduled Caste community.
The petitioner said conflicting explanations and religious statements had emerged after the ceremony. The Congress had also submitted a memorandum to the Governor demanding action.
The strategy could carry particular significance in Uttar Pradesh and Punjab, where Dalit voters constitute a decisive electoral bloc and can influence the outcome in several constituencies.
Kharge also questioned the silence of Prime Minister Narendra Modi and Home Minister Amit Shah on the issue and said they remain silent when something bad happens.
Kharge, in a letter dated September 2, reminded Nadda of his assurance in the Rajya Sabha that the incident would be investigated and strict action taken against those found guilty.
