The bypolls were necessitated after Chief Minister Yogi Adityanath and Deputy Chief Minister Keshav Prasad Maurya vacated the Gorakhpur and Phulpur Lok Sabha seats respectively, following their election to the Uttar Pradesh Legislative Council.

Termed by Adityanath a rehearsal for the 2019 Lok Sabha election, the bye-elections are witnessing a triangular contest involving the ruling BJP, the Samajwadi Party (SP) and the Congress.

The saffron party has fielded Kaushalendra Singh Patel from Phulpur and Upendra Dutt Shukla from Gorakhpur against the SP's Pravin Nishad and Nagendra Pratap Singh Patel respectively. The Congress has nominated Sureetha Kareem for Gorakhpur and Manish Mishra for Phulpur Lok Sabha seat.

Ten candidates are in the fray from Gorakhpur, while 22 candidates are contesting from Phulpur.

Apart from the Provincial Armed Constabulary and homeguards, 65 companies of central paramilitary forces have been deployed to ensure peaceful bypolls.

In Gorakhpur parliamentary constituency, there are 970 polling centres and 2141 polling booths, while in Phulpur, there are 793 polling centres and 2059 polling booths.

According to the Election Commission, there 19.61 lakh voters in Phulpur parliamentary constituency, while there are 19.49 lakh electorate for Gorakhpur Lok Sabha seat.

As many as 4,728 Voter Verifiable Paper Audit Trail (VVPAT) machines are being used in the bypoll and provisions for webcasting from 95 critical booths have been made.

Gorakhpur is significant for the BJP as it is the bastion of the chief minister, who represented the seat in the Lok Sabha five times. Prior to Yogi Adityanath, the seat was  represented in Parliament by his mentor Yogi Avaidyanath thrice.

Phulpur, once represented by India's first prime minister Jawaharlal Nehru, witnessed a saffron surge in the 2014 Lok Sabha elections and Maurya won there.