The MLA said that he sent his resignation letter to Assembly Speaker Nadendla Manohar through fax last night.
"I am for united Andhra," Ramesh Babu said, adding that he resigned from his post as he was upset over his party's decision to bifurcate Andhra Pradesh and carve out Telangana as a separate state.
The Congress and the UPA yesterday unanimously decided to create Telangana state out of Andhra Pradesh, a momentous decision that came in the face of stiff resistance from leaders from non-Telangana region.
The Congress Working Committee, the highest decision-making body, decided to recommend to the central government to form the 29th state which will comprise 10 districts.
Hyderabad, considered the crowning jewel of the Telangana region, will be the joint capital of the newly-proposed state and the other regions - Rayalaseema and Andhra-for a period of 10 years.
A new capital for Andhra will be identified Seemandhra region within this period.