Here are 10 things to know about Rita Bahuguna Joshi:
Rita Bahuguna Joshi, 67, is contesting the Lucknow Cantt constituency against Samajwadi Party candidate and Mulyam Singh's daughter-in-law Aparna Yadav, who is making her political debut.
Ms Joshi quit the Congress in October last year with an attack on Congress Vice President Rahul Gandhi whose staunch supporter she once was. The Congress, in retaliation, has called her a "traitor."
Ms Joshi is from a prominent political family of UP. She is a professor of history at the Allahabad University.
In her 24 years in the Congress, Ms Joshi served in important posts like the head of the party's women's wing and their UP chief. She was also mayor of Allahabad.
In the 2014 national election, Ms Joshi had contested against Union home minister Rajnath Singh from the Lucknow parliamentary constituency and lost.
Her shift to the BJP is seen as the party's counter to the Congress' pitch for Brahmin votes in UP when they projected Sheila Dikshit as their chief ministerial candidate prior to the alliance with Samajwadi Party.
Her resignation came days after Rahul Gandhi's padyatra of the state to draw farmers and invigorate the party cadre and was seen as the BJP's way of demonstrating that local leaders deserted the Congress despite Mr Gandhi's efforts.
Ms Joshi's father, Hemwati Nandan Bahuguna, was a Congress chief minister. He later quit the party and had contested and lost the 1984 national election from Allahabad to actor Amitabh Bachchan, who was then the Congress candidate.
Ms Bahuguna's older brother Vijay Bahuguna is a former Uttarakhand chief minister, who also left the Congress and joined the BJP in 2016.
Appointed UP Congress chief in 2008, Ms Joshi had resigned after the 2012 UP polls, owning responsibility for the party's poor performance. The Samajwadi Party had won that election whereas the Congress came fourth with only 29 of the state's 403 seats.
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