The Bharatiya Janata Party's poor showing in Uttar Pradesh has come as a huge blow to party chief Rajnath Singh, the architect of the saffron strategy for elections in his home state.

Friday's election results, party sources admit, may weaken Singh, who removed Gujarat Chief Minister Narendra Modi from the party's parliamentary board in January.

Hours after the results crashed the BJP out of power race in Uttar Pradesh, senior party leader Murli Manohar Joshi blamed the reverses on the party's election management, which he said required a review at the national level.

His comments virtually signalled the onset of the attack that Singh and former BJP chief M Venkaiah Naidu, who was overall in charge of the party's election management in Uttar Pradesh, could come under from their senior and junior colleagues.

Many in the BJP blame candidate selection for the debacle, citing renomination of almost all sitting MLAs.

They also attribute the debacle to having an alliance with the Apna Dal, a move that took out more than two dozen seats from the BJP's kitty.

"The party took upper caste votes for granted and went on to woo backward sections. It failed miserably. Brahmins have been hugely neglected this time. As a result of which they came in support of the Bahujan Samaj Party," a senior party official said.

The BJP, which has projected veteran leader Kalyan Singh, a Lodh, as its chief ministerial candidate, party sources said, gave inadequate weightage to him during campaign.

"It was the height of mismanagement that the party released its manifesto in absence of its chief ministerial candidate," a BJP leader said. 

In an attempt to keep the Advani camp in good humour, Singh gave overall charge of election management in Uttar Pradesh to Naidu, whom he has been appointing head of almost all party committees over the past few months.

"Now somebody will have to take responsibility from the central leadership as the results are going to have an adverse impact on the party's prospects in the longer term," a BJP official said.

The BJP, which has launched a high-pitched Hindutva campaign, fell well short of retaining its present strength of 73 MLAs, excluding 15 who had already defected.

"An impression gained ground in the general public that we have a tacit understanding with the Samajwadi Party. We were not able to rectify it and lost," another party functionary said.

Voters, he added, perceived the BJP as a party relying heavily on a 'permutation and combination' principle to win power - "This factor cost us dear. We have really been away from electoral politics in all practical terms."

Former prime minister Atal Bihari Vajpayee, the BJP's moderate face, addressed only one public meeting in Lucknow, and that, too, in the fourth phase of the state elections.

He did not launch the saffron campaign in Kanpur, planned jointly with Apna Dal chief Sone Lal Patel and Kalyan Singh, once his critic.

The BJP also did not utilise Modi, its Hindutva icon, for campaign extensively in Rajnath Singh's home state, where the party wooed voters on its ideological plank.

Election results in Uttar Pradesh also came as a setback for the RSS, which used its full strength to ensure the BJP is able to regain lost ground.