KOLKATA: The CPI(M) in Bengal has expressed concern over the rapid growth of RSS in the state during the past five years of Mamata Banerjee’s rule.“After Mamata came to power in 2011, RSS membership in the state has increased five-fold. We are constantly fighting communal forces which are getting indirect patronage from the ruling party ,” CPM MLA and state secretariat member Sujan Chakraborty told ET on Tuesday.The two-day state committee meeting of CPI(M) from December 26 is likely to take up the issue and find ways to tackle the problem.Party insiders even claimed that it was the RSS which had been providing oxygen to the BJP, which in recent elections had increased their tally and is now fast emerging as main threat to the Marxists.RSS chief Mohan Bhagawat will hold a meeting of the organisation here on January 14. Last year too, he held a meeting in Kolkata and the organisation is now busy holding camps at various parts of the state, especially in north Bengal.Jisnu Basu, RSS south Bengal general secretary, however, denied CPIM's claims. “There’s no do ubt that our membership has doubled in 2013, but not five times." Basu said that before 2013, they had 770 units across the state which rose to 1520 after 2013.He also denied CPI(M)'s allegation that their membership has increased during Banerjee 's tenure.“Both the CPI(M) and Trinamool Congress governments tried to thwart our growth. In fact, the Trinamool-run government is not even recognizing several schools which we run in Bengal. The CPM-led government also did the same,” Basu alleged.But CPI(M) has reasons to be worried about RSS’ growth. During the November 19 byelections, BJP has increased its vote share from 12.3% during this year's Assembly polls to 28.3% in the Cooch Behar Lok Sabha bypolls held on November 19. At the Tamluk Lok Sabha by-elections, BJP’s vote share had increased to 15.1% from 5.68% which it had got in the seven assembly segments of the Lok Sabha during this year’s assembly polls.A senior CPI(M) leader, preferring anonymity, said that it was RSS which helped the BJP to improve its electoral position in the state.