Amid seat sharing talks with the Left Front, Congress in poll-bound West Bengal on Thursday sought AICC's nod to initiate formal dialogue with the newly formed Indian Secular Front (ISF) of Pirzada Abbas Siddiqui for a grand alliance of secular parties sans Trinamool Congress. Senior state Congress leader Abdul Mannan, who is also the leader of opposition in the assembly in a letter to party president Sonia Gandhi said he has already started "unofficial dialogue" with ISF and WBPCC president Adhir Chowdhury has visited Siddiqui of Furfura Sharif shrine. "The addition of ISF in the Left-Congress alliance may be a game changer in the ensuing assembly elections ... I have started unofficial dialogue with the ISF and the PCC president visited Siddiqui's place recently. He has discussed the issue with me and is seeking my help because of my personal relation with Pirzada Siddiqui's family since decades," Mannan said.