Modi, however, has himself remained silent over the demand so far.
Bharatiya Janata Party (BJP) leaders say it is an attempt to counter Chief Minister Nitish Kumar's ongoing "Sankalp Yatra" over the denial of special status to the state by the Congress-led union government.
A day ahead of Modi's rally in Purnea district, BJP leaders Sunday said the special status demand will be fulfilled only by him.
"If Modi becomes prime minister, Bihar will be accorded special status by him," the party's national vice president C.P. Thakur said.
Former deputy chief minister Sushil Kumar Modi added: "Narendra Modi understands the problems of Bihar better than others."
BJP national spokesperson Shahnawaz Hussain, who too belongs to Bihar, also echoed the same view. "Bihar will get its long pending special status if Modi becomes prime minister," he said.
However, political analysts say Modi did not mention the demand even once during his Muzaffarpur rally March 3, when he formally kicked off the party campaign in the state.