Former chief minister of united Andhra Pradesh N Kiran Kumar Reddy rejoined Congress on Friday after a meeting with party president Rahul Gandhi in New Delhi.
Reddy had resigned from the party in 2014 in protest against the bifurcation of the state.
After parting ways with the Congress, Reddy floated his own party Jai Samaikyandhra Party and contested elections unsuccessfully.
At one point, speculation was rife that Mr Reddy might join the BJP, but it did not materialise and he had been staying away from active politics for the last four years.
With the state assembly and Lok Sabha elections due next year, the Congress leadership started negotiations with Mr Reddy over the past few months, seeking his to return to the parent organisation.
While conveying his inclination to make a comeback, Mr Reddy has reportedly sought a key position in the All India Congress Committee, befitting his stature.
The former Chief Minister, a bete noire of TDP supremo and chief minister N Chandrababu Naidu, is said to be keen on becoming an AICC General Secretary and has conveyed this to senior party leaders, who were in touch with him in recent days, the sources said.