Kolkata, Apr 9 (UNI) Trinamool Congress general secretary Abhishek Banerjee has written a letter to West Bengal Governor CV Ananda Bose complaining against the Bharatiya Janata Party for allegedly blatantly conspiring with the National Investigation Agency (NIA), Directorate of Enforcement (ED), Central Bureau of Investigation (CBI) and Income Tax Department (IT) against the state ruling party.