Rai unsuccessfully contested against PM Modi in 2014 and finished third in the contest after the BJP leader and AAP's Arvind Kejriwal.
The Congress on Thursday fielded Ajay Rai from Varanasi to take on Prime Minister Narendra Modi, ending speculation on a possible blockbuster electoral duel between Priyanka Gandhi Vadra and the PM in the Uttar Pradesh temple town.
The 'will she, won't she' suspense finally ended in a sort of anticlimax with the party nominating Rai, who unsuccessfully contested against Modi in 2014 and finished third in the contest after the Bharatiya Janata Party leader and Aam Aadmi Party's Arvind Kejriwal.
The Congress also fielded Madhusudan Tiwari from Gorakhpur against BJP's Ravi Kishan, a popular Bhojpuri film star.
Speculation on Priyanka Gandhi making her electoral debut from Varanasi had been rife for the past few weeks and was fuelled after Congress president Rahul Gandhi, to a question on whether he planned to field his sister against PM Modi, said last week, "I will leave you in suspense. Suspense is not always a bad thing."
Priyanka Gandhi herself added to the buzz by saying on Tuesday that she would abide by her party's decision on the matter.
Responding to questions on the decision to not field Priyanka Gandhi from Varanasi, Congress spokesperson Ragini Nayak said, "We have a process and system for fielding candidates. We believe the whole state (Uttar Pradesh) and the whole country needs Priyanka Gandhi's leadership.
"She is the general secretary for a large part of the state. We aim to win maximum seats from that region and voters are impacted by her leadership and simplicity."
"Her (Priyanka Gandhi's) impact will be on the entire country," she said.
Priyanka Gandhi has proved to be the party's star campaigner with her roadshows and rallies evoking tremendous enthusiasm during the poll campaign, Congress leaders said.
She is expected to play a key role in garnering support for the Congress and tilting the scales in the party's favour on seats which are in the balance.
The Samajwadi Party on Monday declared Shalini Yadav, who joined the party Monday evening, as its candidate from Varanasi.
After years of working in Congress backrooms, Priyanka Gandhi joined full-time politics in February as in-charge of eastern Uttar Pradesh, hoping to change the party's fortunes in the ongoing Lok Sabha election.
Varanasi constituency will go to the polls in the last phase on May 19.
With the announcement of the two seats, the Congress has named candidates for 424 seats in all.
Prime Minister Modi will file his nomination papers for the Varanasi Lok Sabha seat on Friday in the presence of senior National Democratic Alliance leaders, including Janata Dal-United president Nitish Kumar and Shiv Sena chief Uddhav Thackeray.
In 2014, Modi won the seat by a margin of over three lakh votes against Aam Aadmi Party leader Arvind Kejriwal.
While Modi got over 5,81,000 votes, Rai managed about 75,000 votes.