The seat has been held numerous times by Samajwadi Party MP Azam Khan and it fell vacant after he was elected to the Lok Sabha in May.
While Congress and the BSP have announced their candidates on the seat, the Samajwadi Party and the BJP are keeping their cards close to their chest.
The Bahujan Samaj Party has named Zubair Masood Khan, a former official of the Customs Department as its candidate. The party is hoping to forge a Dalit-Muslim alliance and wrest the seat from the Samajwadi Party.
The Congress has further queered the pitch by fielding another Muslim candidate, Arshad Ali Khan Guddu.
Rampur has a 70 per cent Muslim population, followed by 28 per cent Hindus, including Dalits.
Azam Khan had won the 2017 Assembly elections by garnering 47.7 per cent votes.
"It is clear that Congress and BSP are playing the BJP game by fielding Muslim candidates and dividing the Muslim votes which could work to BJP's advantage," said Rashid Masood, a journalist.
According to sources, the Samajwadi Party had earlier planned to field SP chief's wife Dimple Yadav from the Rampur seat but after the manner in which the BJP government has been targeting Azam Khan and attempting to demolish his clout in the constituency, the party leadership seems to have developed cold feet.
The party knows that a division of Muslim votes in the prevailing political situation could work to its disadvantage.
"This is the one seat that was held by SP among the 11 assembly seats where bye-elections are being held and it is imperative for the party to retain the seat," said the journalist.
If sources are to be believed, the BJP may name Jaya Prada as its candidate and take the Rampur battle to the next level, knowing the legendary battle between Jaya Prada and Azam Khan.
A senior Samajwadi Party leader, meanwhile, said that the party could hope to retain the seat if it fields someone form Azam Khan's family.
"I know we will be accused of nepotism but we can also play the victim card and gain sympathy of the voters. The Yogi government has gone overboard in targeting Azam Khan-the district administration has even booked his dead mother in an encroachment case," the leader said.
Interestingly, a large number of Azam Khan's supporters are upset with the Samajwadi Party for not supporting him in his hour of crisis.
"The party should have taken to the streets. Mulayam Singh called for a state wide agitation but Akhilesh Yadav did not even support his father on this issue.
"Azam Khan is one of the founding members of the party and certainly deserved greater support. We will definitely stand by Azam Khan and his family but this may not be the case if someone outside the family gets the SP ticket," said a Khan supporter on condition of anonymity.
( With inputs from IANS )