Here are 10 things to know about Rita Bahuguna Joshi:
Rita Bahuguna Joshi, 67, was the Congress lawmaker from the Lucknow Cantt assembly constituency. She resigned her seat today as she quit the Congress.
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 its 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. He won.
Her shift to the BJP is seen as the party's counter to the Congress' pitch for Brahmin votes in UP by projecting former Delhi chief minister Sheila Dikshit for chief minister.
The move comes days after Rahul Gandhi's tour of the state to draw farmers and invigorate the party cadre and is seen as the BJP's way as demonstrating that local leaders are deserting 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 the Congress candidate.
Ms Bahuguna's older brother Vijay Bahuguna is a former Uttarakhand chief minister, who too left the Congress and joined the BJP earlier this year.
Appointed UP Congress chief in 2008, Ms Joshi had resigned in 2012, owning responsibility for the party's poor performance. The Samajwadi Party had won that election, the Congress came fourth with only 29 of the state's 403 seats.
Ms Joshi, who resigned today with a no-holds-barred attack on Rahul Gandhi and his leadership, was once seen as his staunch loyalist. After the 2012 debacle she had defended Mr Gandhi saying he "did a brilliant job" as the party's star campaigner.
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