Phulpur has been represented by India's first Prime Minister Jawaharlal Nehru and later became the stronghold of Mayawati's Bahujan Samaj Party. The seat is important for the BJP as the party won the seat for the first time with Keshav Prasad Maurya contesting the 2014 Lok Sabha election. After 2017 UP Assembly Elections, the seat was vacated by Mr Maurya as he took over as the deputy chief minister.
The elections have assumed greater significance in light of changed political dynamics in the state. To topple the BJP, arch rivals Bahujan Samaj Party and the Samajwadi Party have turned friends from foes for the first time in 25 years. While the BSP has not fielded any candidate from the seat, former chief minister and party chief Mayawati announced that her party would "vote for a candidate who will be in a position to defeat the BJP". Chief Minister Yogi Adityanath had slammed the SP-BSP understanding as "the coming together of a mongoose and a snake when a storm brews". On the Phulpur by-election day, Chief Minister Yogi Adityanath said that he was confident of "victory margins as big as in 2014" and was "not worried at all".