Counting of votes will take place on Tuesday in three Lok Sabha and 29 assembly constituencies spread across 13 states and the Union Territory of Dadra and Nagar Haveli where by-elections were held on October 30.
INLD leader Abhay Chautala, who quit the Haryana assembly in protest against the three new central farm laws, Congress' Pratibha Singh, wife of late chief minister Virbhadra Singh, former national footballer Eugeneson Lyngdoh and ex-minister from Telangana Eatala Rajender are among the prominent candidates whose fate will be decided.
The assembly by-elections which saw a high turnout were held in five seats in Assam, four in West Bengal, three each in Madhya Pradesh, Himachal Pradesh and Meghalaya, two each in Bihar, Karnataka and Rajasthan and one seat each is in Andhra Pradesh, Haryana, Maharashtra, Mizoram and Telangana.
Out of the 29 Assembly seats, the BJP had won in around half a dozen constituencies earlier, the Congress had nine, while the rest were with the regional parties.
The seats where Lok Sabha by-elections were held are Dadra and Nagar Haveli, Mandi in Himachal Pradesh and Khandwa in Madhya Pradesh. In all the three Lok Sabha constituencies, the sitting members had died.
The Mandi seat fell vacant after the death of Ramswaroop Sharma (BJP) in March.
The bye-election to the Khandwa parliamentary constituency was necessitated following the death of BJP member Nand Kumar Singh Chauhan while in Dadra and Nagar Haveli, it was due to the demise of Independent Lok Sabha member Mohan Delkar.
In Mandi, Pratibha Singh is pitted against BJP's Khushal Singh Thakur, a Kargil war hero.
In Meghalaya, former national footballer Eugeneson Lyngdoh is contesting the election from Mawphlang on a United Democratic Party (UDP) ticket.
He is up against former Congress MLA Kennedy C Khyriem and a sitting member of the district council (MDC) from the NPP, Lamphrang Blah.
In Haryana, the by-election to Ellenabad Assembly constituency was necessitated by the resignation of Indian National Lok Dal (INLD) leader Abhay Chautala as MLA in protest against the Centre's new farm laws.
Chautala, son of INLD chief Om Prakash Chautala, is contesting against Congress nominee Pawan Beniwal and BJP-JP candidate Gobind Kanda, the brother of Haryana Lokhit Party chief and legislator Gopal Kanda.
It is an important contest for the Chautalas as Abhay Chautala had won the 2010 bypolls from Ellenabad when Om Prakash Chautala vacated the seat, and then retained it in 2014 and also in 2019 Assembly polls, when he was the lone INLD MLA in the House.
In the Dadra and Nagar Haveli Lok Sabha constituency, seven-time independent MP Mohan Delkar's wife Kalaben Delkar is contesting as Shiv Sena candidate against BJP's Mahesh Gavit and Congress' Mahesh Dhodi.
In Huzurabad Assembly constituency in Telangana, the ruling TRS, opposition BJP and Congress locked in a triangular contest.
The by-election was held following the resignation of Eatala Rajender in June after his removal from the state Cabinet over allegations of land grabbing. Rajender, who dismissed the allegations, had quit the TRS and is contesting on a BJP ticket.
The result is significant for the BJP as it aims at emerging as an alternative to the ruling TRS in the 2023 Legislative Assembly elections.
In Assam, the ruling BJP has fielded candidates in three seats leaving the other two to alliance partner UPPL.
The Congress put up nominees in all five, while its former allies, the AIUDF and the BPF, are contesting in two and one seats respectively.
In West Bengal, TMC heavyweight Udayan Guha is looking to reclaim Dinhata seat, which the BJP had snatched from him in the April elections.
The by-election was held following the resignation of Nisith Pramanik, now Union Minister of State for Home Affairs, as he chose to retain his Lok Sabha membership.
Bypolls to Dinhata and Santipur are seen as a prestige battle for the BJP, which is currently grappling with an exodus of MLAs and senior leaders.
In Santipur, BJP MP Jagannath Sarkar had resigned from the assembly.
In Rajasthan, the bypolls were necessitated due to the demise of Congress MLA from Vallabhnagar Gajendra Singh Shaktawat and BJP legislator from Dhariawad Gautam Lal Meena.
In Vallabhnagar, the ruling Congress party has given a ticket to Gajendra Shaktawat's wife, Preeti Shaktawat, while the BJP has fielded Himmat Singh Jhala.
The Congress has fielded Nagraj Meena in Dhariawad against BJP candidate Khet Singh Meena.
Both the BJP and the Congress are keen to win the results will send a message across the state about the performance of the Ashok Gehlot government, which is facing a challenge from the Congress faction led by Sachin Pilot.
In Karanataka, the by-election was necessitated following the death of Sindgi JD(S) legislator M C Managuli and BJP's C M Udasi from Hangal and will be the first electoral test for Chief Minister Basavaraj Bommai, who had replaced B S Yediyurappa.
Counting of votes will also take place in Andhra Pradesh's Badvel seat, earlier held by the YSRC, Deglur in Maharashtra, which was held by the Congress, and Tuirial assembly seat in Mizoram.