Srihari, once a lecturer, had been with the TDP since its inception and served as an MLA for four terms. He was also a minister in the Chandrababu Naidu Cabinet in the late 1990s.
"The TDP has completely failed the people and lost its credibility. Only cash-rich industrialists were getting prominence in the party at the cost of sincere workers," Srihari alleged at a media conference in his hometown Warangal.
Srihari, who represented the TDP at the all-party meeting in New Delhi on Telangana, said the party was not respecting the sentiments of people of the region.
However, he announced his resignation today but did not indicate his future plans.