GUWAHATI, March 18 -- Senior Congress leader and Lok Sabha MP from Assam Pradyut Bordoloi on Tuesday resigned from the party, sending a jolt to the party's state unit just ahead of the assembly election. Bordoloi was in-charge of the party's manifesto committee for the coming polls. In a letter sent to Congress president, Mallikarjun Kharge, he said: "With an overwhelming sense of sadness today, I hereby tender my resignation from all posts, privileges and primary membership of the Indian National Congress." HT has seen the letter. Last month, former Congress state president, Bhupen Kumar Borah had quit the party and joined the ruling BJP. Just before the news of Bordoloi's resignation, Assam chief minister had said: "I have not had any int...