The party chief has called for a meeting of district presidents, zonal in-charges and other concerned office-bearers.
Analysts say the results have come despite Priyanka not campaigning much and the outcome may well have been different if her team had put in more effort.
Hitting out at the BJP, Yadav said the people voted against the saffron party and the politics of hatred, casteism and corruption.
Of the 11 seats where bypolls were held, the BJP had sitting MLAs in nine and the SP and BSP in one seat each. The BJP managed to retain its forts in eight of the nine but lost Zaidpur to the SP.
Lucknow Cant, Govindnagar, (Kanpur), Pratapgarh, Balha (Bahriach) and Gangoh have all gone to the ruling BJP and its allies while Zaidpur in Barabanki was won by the Samajwadi Party.
The Ghosi seat which fell vacant following the resignation of MLA Phagu Chauhan after he was appointed the Governor of Bihar is another tough battle for the BJP.
The BJP is eyeing a clean sweep in the bypolls in order to increase its tally in the state legislative assembly.
Gangoh assembly constituency in Saharanpur will go to bypoll along with 10 other seats on October 21 while the results would be announced on October 24.
Pal, a district-level BJP functionary who was earlier with the Samajwadi Party, has now been announced as the candidate from the former union minister Anupriya Patel's party, Apna Dal (S).
The Rampur Assembly seat fell vacant after Azam Khan was elected to the Lok Sabha in May this year.
While Sudhakar Singh will be the party's candidate from Ghosi, Nirbhay Singh Patel will be SP candidate from Manikpur.
While four names were for Assam, five were for Kerala and 10 for Uttar Pradesh. Bihar, Chhatisgarh, Meghalaya, Madhya Pradesh, Rajasthan and Telangana had one name each in the list.
Having learnt its lessons from the four bypoll defeats of 2018, the BJP, which has the most to lose, is taking no chances. It is going to be a four-cornered contest with no alliance on the horizon.
The new organisational reshuffle is being viewed as an initiative of the BSP chief to strike a caste calculus by bringing Muslims, Backwards and Dalits at par.
The fall of Gorakhpur seems to be much beyond political comprehension as the voters chose to go with opposition against a BJP candidate who had no association with Gorakhnath Mutt.