Gandhi, BSP's Brahmin leader Pawan Pandey and 12 others are up against 'Raani sahiba' Amita Singh who is fighting her first parliamentary election on Congress ticket after her husband and sitting MP Sanjay Singh, known as 'Raja sahib', was nominated to Rajya Sabha by the party a few months ago.
Pandey has more than 30 cases, including serious charges of murder and rioting against him. While Congress had won from this seat seven times from 1951-1984, BJP won it thrice between 1991 and 1998. Mayawati's BSP secured the seat twice in 1999 and 2004. In 2009, Singh defeated BSP's Mohammed Tahir by 98,779 votes.
Political circles are abuzz with talk of "lotus bloom" after Gandhi's advent here from Pilibhit, where he last time won by a whopping margin of 2.8 lakh votes.
Observers say Congress finds itself on a sticky wicket at Sultanpur seat, adjacent to Nehru-Gandhi family bastions of Raebareli and Amethi, with SP and BSP also having fielded strong local candidates, who are campaigning aggressively.
Congress' famed grip in nearby areas, however, appears to be on the wane as it had lost in all five assembly segments of Sultanpur in 2012 Assembly elections.
Eyeing Muslim votes, Samajwadi Party has fielded Shakeel Ahmed, a transporter. Muslim youths in Rasoolabad, Harakpur, Meenapur, Aliganj and Islamganj seem inclined towards SP, though a divide in Muslim votes primarily between SP and Congress cannot be ruled out.
What also works to Ahmed's advantage, say political pundits, is that BSP has dropped its Muslim candidate, Tahir, a former MP, who was the runner up in the 2009 polls.
Some say it is too early to write off the strength of Singh as the erstwhile 'raja' has a strong loyal band of supporters, who would rally behind Amita as well.
Sultanpur has a sizeable Dalit population. With BSP having replaced Tahir with Pandey, all eyes are on Dalit-Brahmin combination votes. BSP -favourite of Dalits- at the moment appears to be stealing a march over rivals when it comes to identity politics, the core of parties in the Hindi heartland.
On the other hand, BJP is hoping that caste combinations crumble in the constituency under the impact of Gandhi surname and 'Modi wave', marking a turnaround for the party here after its vote share hit lows in past three elections.
According to a rough estimate, OBCs are 27 per cent of a total of over 14.3 lakh voters here, followed by 24 per cent Dalits, 21 per cent of Muslims, 18 per cent Brahmins and 6 per cent Thakurs, among others.
Though Varun is contesting on a BJP ticket, he has rarely taken the name of his party's Prime Ministerial candidate Narendra Modi riding on whose "wave", BJP hopes to sweep Uttar Pradesh.
Instead, Maneka Gandhi's son has chosen to highlight his father, the late Sanjay Gandhi. But his rival Amita is quick to dismiss any effect saying Varun's father had represented the nearby Amethi and not Sultanpur, where the mere mention of Nehru-Gandhi family association still evokes awe.
A former MLA, who had lost her Amethi Assembly seat in 2012, Amita Singh is confident that she would win and Varun Gandhi's attempt to hitch a ride to Parliament on Gandhi surname won't succeed in Sultanpur that votes on May 7. Throughout his roadshow, there was no picture of Modi in the placards amid slogans like "Varun nahin yeh aandhi hai, doosra Sanjay Gandhi hai".
Interestingly, a senior Congress office bearer, speaking on condition of anonymity, told PTI that a number of party workers who were annoyed with Sanjay Singh for one reason or the other are silently working for Varun.
"Backwards were ignored in the organisation. Grassroots workers were sidelined at the expense of newcomers," says a district general secretary of Congress, Srinath Verma, when asked about the problems the party faces in these polls.
Understandably, Priyanka Gandhi, bowing to the demands from Sanjay Singh camp, made an appeal to party workers a fortnight back, asking them to work to ensure the victory of Congress candidate Amita Singh.
She said that though Varun is her brother, he has "gone astray" by joining BJP. While Varun maintained that his silence and dignity should not be construed as weakness, Priyanka hit back saying it's an "ideological battle" and not a "family tea party".
Varun's father Sanjay had represented Amethi from 1980 to 1981 before his death in a plane crash. Sanjay Gandhi had also contested the seat in 1977, but had lost then.
A senior Congress leader from the area, who is close to Gandhis, says that Varun wanted to contest from Sultanpur in 2009 itself but since it was his first election, his mother Maneka Gandhi fielded him from the safe seat of Pilibhit, which she had won five times in past.
"Varun has come here to reclaim the seat," he argued. AAP's Shailendra Pratap Singh is campaigning aggressively in the city but pundits say the new party is yet to catch the imagination of the people in Awadh region.