The announcement was made by the Congress party spokesperson Randeep Surjewala in Delhi. Surjewala said the party decided to field a person who had worked at the grassroots level in Varanasi. "Ajay Rai's name was finalised after discussions in the party."
He said Varanasi will not only be a battle between political parties but also between "ideologies".
"It will be a contest between those who break and those who make, those who divide and those who join, those who want to take the country backwards and those who want to empower it," Surjewala said.
Stating that the Congress represents the forces of unity, the spokesperson sought support for Rai.
"We appeal to all that they should support the Congress and its candidate," he said.
Who is Ajay Rai?
Rai is a sitting MLA from the newly-formed Pindra constituency.
He had ended ties with the BJP following rift over giving ticket to Murli Manohar Joshi for the Varanasi seat in 2009.
Then he contested on Samajwadi Party (SP) ticket after being denied BJP ticket in 2009.
Ajay Rai has a strong presence among Bhumihar and Brahmin voters in Varanasi.
After that, Rai joined Congress.
He is a Bhumihar who has a good presence in the constituency, among Bhumihars and Brahmins voters. He shot into prominence when he defeated the CPI stalwart Udal in Kolsala constituency in the 1996 UP elections.
He has since won each assembly election and has been a five-time MLA.
Earlier, the name of Rajesh Mishra, former MP from Varanasi, was doing the rounds.
Varanasi- The tough battleground
Other contestants who will face Modi in Varanasi are- Quami Ekta Dal's (QED) Mukhtar Ansari, SP's Kailash Chaurasia, BSP's Vijay Prakash Jaiswal, TMC's Indira Tiwari and CPIM's Hiralal Yadav.
Varanasi became the "most sought after" constituency for the Congress legislators. Prominent leaders like P Chidamabram, Digivjay Singh, Anand Sharma, Rashid Alvi had expressed their desires to contest against Modi.
Varanasi goes to the polls May 12, the last day of polling for the nine-phase Lok Sabha election.
Varanasi has become the centre of attraction for all, when BJP confirmed that Modi would contest from the city.
Later, AAP leader Arvind Kejriwal too announced that he would challenge Modi by contesting from Varanasi, Uttar Pradesh.
In UP, almost all seats have a Muslim population of over 15-20 per cent while in some constituencies in Delhi, the minority section makes up about 20-22 per cent of the population.