THIRUVANANTHAPURAM: CPM and Congress have decided to co-operate in the upcoming Lok Sabha elections in Bengal. A discussion is being held among the leaders of political spectrum in Kerala regarding the co-operation which can be experimented in Kerala as well. BJP leader K Surendran has come forward saying that such discussions show the increasing strength of BJP. He said that BJP’s victory is evident in the domestic surveys conducted by various parties and LDF-UDF fronts may not go for a public co-operation like the one in Bengal. He also said that the parties are planning to exchange votes.