TRS and Congress candidates are locked in a direct fight though the Bharatiya Janata Party (BJP) and Telugu Desam Party (TDP) candidates are also hoping to pull it off.
First bypolls since Lok Sabha polls, it is expected to be an acid test for the ruling party as it is being held amid the ongoing indefinite strike by employees of state-owned Telangana State Road Transport Corporation (TSRTC), which has brought the opposition parties and other anti-TRS forces together.
Little over 2.36 lakh voters, nearly half of them women, will decide the political fortunes of 28 candidates including 15 Independents.
Authorities have set up 302 polling centres in the constituency located in Suryapet district, once considered a Congress stronghold.
Huzurnagar came into existence as a result of delimitation of constituencies in 2009. Congress party's N. Uttam Kumar Reddy won the seat in successive elections in 2009, 2014 and 2018.
Following his election to Lok Sabha from Nalgonda constituency, Uttam Kumar Reddy resigned from Assembly, necessitating the by-election for Huzurnagar. Congress has fielded his wife Padmavati Reddy in the by-election.
As Uttam Kumar Reddy is also the president of Congress party's state unit, the bypoll is a prestige battle for him. Leading the party campaign, he sought votes on the basis of development works undertaken by him in the constituency during last decade.
TRS, on the other hand, is determined to wrest the seat from Congress. It has once again fielded Saidi Reddy, who lost to Uttam Kumar Reddy in December 2018 elections by a margin of 7,466 votes.
The Congress party then had alliance with TDP, Communist Party of India (CPI) and Telangana Jana Samithi (TJS). This time it is going alone, enjoying the support of only TJS.
TDP, which had stayed away from Lok Sabha polls in Telangana, choose to field its candidate in the bye-election to send a message that it is alive in the state.
Huzurnagar is one of the segments of Nalgonda Lok Sabha seat and in the Lok Sabha elections held in April, Congress had increased its majority to 12,993 votes.
The low-key campaign saw the ruling party urging people to vote for the development and the welfare schemes implemented in the state during last six years.
After retaining power in December 2018 with a landslide victory, TRS suffered setback in Lok Sabha polls with BJP winning four and Congress three seats to deny it a clean sweep.
However, the ruling party staged a comeback to score massive victory in rural local body polls in June. It is confident of continuing the victory march.
The TRS had to face some anxious moments in the campaign due to the strike by TSRTC employees, which entered its 16th day on Sunday. The strike brought together all opposition parties and those groups who have been opposing Chief Minister K. Chandrashekhar Rao. The state-wide shutdown called by the striking employees on Saturday was support by all anti-TRS forces.
The ongoing strike's tough handling by the government also had its impact on TRS as Communist Party of India (CPI) withdrew its support to the ruling party.
CPI, which fought Assembly elections in alliance with Congress, surprised all by declaring support to TRS earlier this month. However, the party reversed its decision within 15 days to protest the government's move to sack 48,000 striking employees of TSRTC.
TRS campaign also suffered set back as the Chief Minister and TRS president's only election rally was cancelled due to rains. His son K.T. Rama Rao, who is a cabinet minister and working president of the party, conducted road show. Another minister Jagdish Reddy, who comes from the same district, ran the party campaign along with other leaders.
TRS leaders see good prospects for their candidate as they believe both BJP and TDP will cut into anti-TRS votes.
Political analysts say the bye-election is crucial for Congress as a victory in Huzurnagar could give it a moral boost against TRS, which not only lured 12 Congress MLAs to its ranks but also got them merged with the ruling party. Leaving with just six seats in 119-member Assembly, Congress lost the status of main opposition party.
A victory in Huzurnagar may help Congress to put pressure on the defectors to quit and seek fresh election.
( With inputs from IANS )