A day after resigning from the Bharatiya Janata Party (BJP), veteran tribal leader Nand Kumar Sai on Monday joined the ruling Congress in Chhattisgarh where the Assembly polls due this year-end. Addressing mediapersons after joining the Congress, Sai said it was a tough decision for him to quit the BJP and claimed it was no longer the party which it used to be "during the time of Atal ji and Advani ji”. Sai submitted his resignation to state BJP president Arun Sao on Sunday and claimed his colleagues were hatching conspiracies and levelling false allegations to tarnish his image, which had left him deeply hurt. The 77-year-old leader, a former three-term Lok Sabha member and three-time MLA, served as the BJP's state president in both Chhattisgarh and undivided Madhya Pradesh in the past and has considerable influence in tribal-dominated parts of Surguja division (northern Chhattisgarh).