The BJP-backed National Democratic Teachers Front (NDTF), in its letter to the minister, also dubbed the event as an "unpardonable anti-national" act.
"We write to express our concern at the diabolically planned attempt by politically motivated groups to foment trouble and turmoil amongst students of various universities to destabilise the existing structures of governance.
Endorsing Irani's stand on the event presented by her in Parliament, the teachers said there may be an argument on strict legalistic terms as to what constitutes sedition, but it is crystal clear that what had happened in JNU was "unpardonable anti-national" act which has to be both "condemned and curbed".
"Yet those who raise such slogans and those who protect them with convoluted arguments swear by the right to freedom and dissent provided by the same Indian Constitution.
JNU is caught in a row over an event against the hanging of Parliament attack convict Afzal Guru during which anti-national slogans were allegedly raised.