Shukla, a former Lok Sabha MP, resigned from BJP in October last year, alleging she was being "continuously neglected" by senior leaders.
"The era of Atal Bihari Vajpayee and L K Advani in the BJP has come to an end," 63-year-old Shukla told PTI.
The BJP is now being run by a group of individuals including Narendra Modi, Rajnath Singh and some others, she claimed.
Karuna Shukla had a 32-year-long association with BJP.
Shukla, who had a 32-year-long association with BJP, said it was a very painful decision for her to leave the party for which she had worked from the ward to the national level.
The Congress candidate from Bilaspur Lok Sabha constituency, Shukla, daughter of Vajpayee's elder brother, alleged she felt "miserable" in the Chhattisgarh party unit under the leadership of Chief Minister Raman Singh and that BJP treated her "badly."
To a question, she quipped though BJP did not treat her well, it may give proper treatment to Ram Kripal Yadav, a former close aide of RJD president Lalu Prasad Yadav who has been given ticket by the saffron outfit from Pataliputra, and veteran leader Jagdambika Pal, who recently quit Congress amid speculation that he was warming up to BJP.
In the 2009 Lok Sabha elections, Congress won only one seat from Chhattisgarh, but Shukla expressed confidence that this time the party will win at least four seats.