Big political showdown in poll-bound West Bengal. PM Narendra Modi staged a massive rally in Kolkata's iconic Brigade Parade ground. In his speech, PM attacks on Mamata Government. PM says Mamata Banerjee betrayed the people of Bengal. PM's rally is said to be a culmination of the "Parivartan Yatra" launched by the saffron party in February last month. Watch the video to know more.