"Modi is a communalist and it is not proper on the part of anybody to invite him for a function like this," CPI(M) state secretary Pinarayi Vijayan said at a press meet here.
Modi is scheduled to attend one of the sessions organised as part of the birthday celebrations of Amritanandamayi at the ashram at Vallikkavu in Kollam district on September 26.
A few months back, CPI(M) and other Left parties had raised objections to Modi's visit to the Sivagiri Mutt at Varakala, founded by the 20th century saint-reformer Sree Narayana Guru.
Modi, who shrugged off the criticism, said in his speech at the Mutt that the resentment voiced by Left against his visit only showed that "untouchability" still prevailed in politics despite the evil being eradicated in the society due to efforts of reformers like Narayana Guru.