"BJP in its new avatar has digressed from the path of their tallest leader Atal Bihari Vajpayee," Kumar said at an election rally at Madhusarwa village here in Arwal district.
The three contentious issues in the BJP manifesto released on Monday were kept out of NDA agenda during regime of Atal Bihari Vajpayee in which Kumar was a minister.
Criticising BJP for bringing back Ayodhya issue into focus, Kumar said, "Kasam Ram ki khate hai mandir wahi banayege, par tarikh nahin batayenge (we vow in the name of Lord Ram to build the temple there, but will not give the date for it)," he said rephrasing the BJP slogan.
"Insan ke sath sath bhagwan ko bhi dhoka de rahe hai (Not just people, they are cheating even the god)," he said.
He also accused the saffron party of "playing a joke" in the name of special category status for Bihar.
"BJP leaders have time and again committing to provide special status to Bihar if voted to power, but it is not part of their manifesto," he said.
Highlighting development works of his government in the state in last 8 years, Kumar warned if the people did not strengthen his hands in the parliamentary elections, the development process would be halted.
Attacking BJP prime ministerial candidate Narendra Modi, he asked "whether a person whose very name triggered fear among Muslims can keep the country united?"