Two-time Congress MLA Sushanta Borgohain, who won from the Thowra seat in upper Assam, tendered his resignation from the primary membership of the party over differences with the state leadership.
In his resignation letter addressed to state Congress president Bhupen Bora, Borgohain blamed the present "internal political atmosphere" in the party for his resignation.
"Unfortunately, all the efforts in this direction proved futile, compelling me to take this ultimate decision and the exact reasons for such a painful move on my part have already been conveyed to the senior leadership of the party both in the state and at the centre," Borgohain wrote in his letter.
Sushanta Borgohain is the second Assam MLA from the Congress to quit the party since the Himanta Biswa Sarma-led BJP government took charge in the state. Last month, four-time MLA from Mariani Rupjyoti Kurmi quit the Congress to join the BJP.