Telangana Rashtra Samiti candidate Pocharam Srinivasa Reddy won the bypoll from Banswada assembly constituency in Nizamabad district of Andhra Pradesh on Monday.
Reddy defeated ruling Congress' Srinivas Goud by a margin of 49,889 votes.
The by-election was necessitated following the resignation of Pocharam in March this year. He had quit his assembly membership as well as the Telugu Desam Party on the statehood issue and joined the TRS.
The TDP and the BJP did not field candidates in the by-election held on October 13. Of the 1,22,872 votes polled, Pocharam secured 83,245, while Goud got 33,356.
With Pocharam's victory, the TRS' strength in the 294-member AP Assembly rose to 12. However, 11 TRS MLAs have recently submitted their resignations to the Assembly Speaker Nadendla Manohar, demanding creation of Telangana state. The TRS has not yet announced whether Pocharam too would be asked to follow their suit.
Pocharam termed his win as the victory of people of Telangana.
