The Congress has complained to the Election Commission of India alleging that a caller tune message by Gujarat Chief Minister Vijay Rupani about precautions to avoid coronavirus is a breach of the Model Code of Conduct.
The state would be having byelections to eight assembly constituencies on November 3.
Mr Rupani rubbished the Congress' allegation and said the message was only part of efforts to educate people to be safe during the festive season.
In a letter to the ECI and Chief Electoral Officer of Gujarat, state Congress leader Nishit Vyas sought action against Mr Rupani and the ruling BJP.
Mr Rupani has "affirmatively committed an act of undue influence on the voters in the name of religion by displaying and publishing his speech as a caller tune prior to ringing of the mobile phone of all mobile telephone operators," said the complaint, dated Friday.
In the message, Mr Rupani advises people to celebrate the Navratri festival with restraint by ensuring social distance, and using masks and sanitizers.
The Congress claimed that his message as a caller tune was introduced after the code of conduct came into force.
"(Rupani) is influencing the voters and public in the name of religion and depicting himself as one of the messiahs and protectors of Hindu religion....this is a clear misconduct and, therefore, he is required to be prosecuted for election offence either under the provisions of the Indian Penal Code, 1860 or the Representation of People's Act, 1951," the complaint said.
The opposition party also accused the BJP and its candidates of hiding the details of expenditure incurred on the caller tunes by paying telecom operators.