No matter which way the result goes, the Mainpuri by-poll is set to make electoral history.
If the Bharatiya Janata Party (BJP) wins, it will be the first victory or the BJP or its former avatar the Jan Sangh in the parliamentary constituency since the first post-independence general election in 1951-52.
If, however, the Samajwadi Party candidate Tej Pratap Singh Yadav wins, it will be the first time in the Lok Sabha's history that three generations of a political family will be sitting together in the house.
While Samajwadi Party chief Mulayam is already in the Lok Sabha from Azamgarh, the next generation in the lower house is represented by his nephew Dharmendra Yadav and daughter-in-law Dimple Yadav.
If Tej wins, the third generation too will sit in the same house, an unprecedented occurrence in India's Parliamentary history. Since 1991, the Mainpuri seat has been won either by Samajwadi Party chief Mulayam Singh Yadav or his nominee even in the pre-SP days.
The voters there are unfazed by political waves. Despite the Ram Temple wave in 1991, Mulayam's nominee Uday Pratap Singh Yadav won the election on the Janata Party ticket.
Twenty-three years later, the Modi wave could not upset Mulayam's applecart in Mainpuri and he won the seat by 3.64 lakh votes in the 2014 general election.
Mulayam made his maiden entry into the Lok Sabha in 1996 from Mainpuri. In all, he has won the seat five times. This is the second time a by-poll is being held in the constituency because of Mulayam's resignation from the seat.
Mulayam had first vacated the seat in 2004, choosing to remain chief minister of Uttar Pradesh. The ensuing by-poll launched his nephew Dharmendra Yadav in Parliament.
Now, it is the turn of Mulayam's grandnephew Tej Pratap Singh Yadav. Mulayam has left no stone unturned for Tej's victory and called it "Izzat ka sawaal (a matter of prestige)".
Leaving nothing to chance, he made his brother and senior minister Shivpal Singh Yadav the in charge of Tej's election. Shivpal ran several rounds of a grassroots level campaign in the constituency.
The party's national general secretaries Ramgopal Yadav and Naresh Agrawal too toured the constituency. Badaun MP Dharmendra Yadav too campaigned here.
Mulayam and chief minister Akhilesh Yadav, who did not seek votes in any of the 11 assembly constituencies going to the by-polls, campaigned for Tej.
In fact, Mulayam addressed two rounds of rallies, something that he hadn't done even for himself in the April-May general elections.
It was Tej who handled Mulayam's campaign and the SP chief trusted him so much that he hadn't visited the constituency in the run-up to the polls at all.