Voting begins for bypolls in West Bengal's Sabang, Arunachal Pradesh's Pakke-Kessang and Likabali, and Uttar Pradesh's Sikandara.
The BJP has nominated Antara Bhattacharya while the Congress has fielded Chiranjib Bhowmick, a local leader. The CPI(M)'s Rita Mandal will contest the seat as a Left Front candidate.
The choice for around 245,259 voters will be between Trinamool Congress candidate Gita Rani Bhunia, wife of Manas Bhunia who had in 2016 won the Assembly polls with 59.6 per cent of the votes, his replacement in the Congress, local leader Chiranjib Bhowmick, Left candidate Rita Mandal and BJP hopeful Antara Bhattacharya.
The Congress had fought the 2016 assembly polls in the state in alliance with the CPI(M)-led Left Front and Bhunia had secured 59.70 per cent votes. The TMC had then bagged 36 per cent votes.
The BJP candidate had polled only 2.6 per cent votes in the 2016 assembly poll.
The Sabang bypoll election is significant as it comes only a few months ahead of the rural elections in the state in 2018.
The rural polls are crucial since it will indicate the popularity of BJP that has set a target of winning 22 seats - half of the 44 Lok Sabha constituencies in Bengal - in the 2019 Lok Sabha polls.
BJP is substantially depending on Roy to pull off a magic in the rural and Lok Sabha elections. The Sabang bypoll will test whether Roy can stand on his own without the halo of Mamata Banerjee, under whom he worked so far.
"Mukul Roy has great organisational skills. Local workers are going to every voter and telling him about the achievements of the Union government. They are also telling the people how Bhunia betrayed their trust and switched to TMC," said district BJP leader Tushar Mukherjee.
TMC leaders such as MP and Mamata Banerjee's nephew Abhishek, education minister Partha Chatterjee, transport minister Suvendu Adhikari, law minister Chandrima Bhattacharya, party general secretary Subrata Bakshi are holding public meetings in the area. They have all lashed out at Roy.
In Arunachal Pradesh, six candidates are in the fray for the by-election to Pakke-Kessang and Likabali assembly seats in Arunachal Pradesh. Likabali seat fell vacant after death of Health and Family Welfare Minister Jomde Kena passed away on 4 September this year, while by-election to Pakke-Kessang seat was necessitated after the Gauhati High Court had nullified the election of Kameng Dolo from the said constituency during the March 2014 polls.
Voter-Verified Paper Audit Trail (VVPAT) system will be used for the first time in the state of Arunachal Pradesh for the byelection.
In UP, the Sikandara Assembly seat in Kanpur Dehat district is vacant since the demise of BJP MLA Mathura Prasad Pal on 22 July. In the Assembly elections this year, Pal had bagged 87,879 votes, defeating BSP candidate Mahendra Katiyar (Bablu). Ajit Pal Singh is BJP candidate for the bypoll, while Samajwadi Party fielded Seema Sachan and Congress candidate is Prabhakar. BSP is not contesting.