On 30 January 2015, she announced in a press conference at Chennai that she would be resigning from the Congress party alleging that "specific requests" by Rahul Gandhi were the basis of whether industrial projects were given clearances by her ministry, and that he shifted from a pro-environmental position to corporate-friendly stand for the elections in 2014.

Jayanthi studied at Ethiraj College for Women before pursuing law and became a practicing advocate in Madras.

Apart from her commercial practice, she also did pro bono work for a number of social organizations including the All India Women's Conference, and the legal aid board.

She also worked briefly as a newscaster for Doordarshan Kendra, Madras [2][3] Her political career began when she was noticed by Rajiv Gandhi in the 1980s.

During the 90's Jayanthi Natarajan and other leaders from Tamil Nadu who were unhappy with Narasimha Rao decided to break away from the party.

The TMC was allied with the Dravida Munnetra Kazhagam in Tamil Nadu and was a part of the United Front government in the centre.

She also believed, according to the letter, that she was being made a scapegoat for the economic policy paralysis observed in the UPA-II government.