"CPI feels that this is a blot on the freedom of speech. It is not only a failure of the ruling coalition but also shows its totalitarian attitude promoted by Sangh Parivar. This is not an isolated issue as growing intolerance is reflecting across the country.
"If NDA governments at Centre and states really believed in democratic values, they should take action against perpetrators of such violent acts," CPI general secretary S Sudhakar Reddy said in a statement.
He also targeted Prime Minister Narendra Modi for "not learning lessons" to control such incidents, despite a spate of intellectuals and writers returning awards to government-sponsored institutions like Sahitya Akademy.
Activists of Shiv Sena, a constituent of NDA, today smeared black paint on Kulkarni for refusing to cancel an event to launch a book written by former Pakistan Foreign Minister Khurshid Mahmud Kasuri in Mumbai.