The Election Commission on Wednesday sent a show cause notice to Congress president Mallikarjun Kharge, alleging that he prima facie violated the Model Code of Conduct for the Assembly elections by calling Prime Minister Narendra Modi a “terrorist” on April 21.

Kharge had made the comment at a press conference in Chennai on the last day of campaigning for the Tamil Nadu elections.

The Congress chief later clarified that he meant to say that the prime minister was “terrorising” the country’s democratic fabric by misusing government machinery, and that he did not refer to him as a terrorist in the literal sense, the Hindustan Times reported.

The Election Commission said on Wednesday that the use of “intemperate and highly objectionable and dehumanising choice of words by a seasoned politician against a constitutional functionary” appeared to be inconsistent with the standards of public discourse and undermined the dignity of democratic institutions.

The poll panel said it was of the preliminary opinion that Kharge had violated provisions of the Model Code of Conduct, which state that criticism of political parties should be confined to their policies and programmes, past record and work.

It also said that the Congress chief appeared to have disregarded advice expressed in a letter to political parties to observe “utmost restraint and decency” in the election campaign.

The Election Commission directed Kharge to explain his stand on the matter within 24 hours.

The Congress chief had on Tuesday made the remark about Modi while questioning the All India Anna Dravida Munnetra Kazhagam’s decision to ally with the Bharatiya Janata Party.

“How do these AIADMK people, who themselves put the photo of [former chief minister CN] Annadurai... how can they join with Modi?” he had asked. “He is a terrorist...He doesn’t believe in equality. His party won’t believe in equality and justice.”

A day later, a BJP delegation comprising Parliamentary Affairs Minister Kiren Rijiju, Finance Minister Nirmala Sitharaman and Law Minister Arjun Ram Meghwal met the the Election Commission, seeking strict action and an apology from Kharge.

Voting is underway on Thursday in all Assembly constituencies in Tamil Nadu, and in 152 seats in West Bengal. Elections in Assam, Kerala and Puducherry took place on April 9, while the second phase of the West Bengal election will take place on April 29.

The results in all states will be announced on May 4.