The development indicates growing warm vibes between the two parties after the BJP ran a strong campaign against the BJD in the recent Lok Sabha and assembly polls, emerging as the main challenger to Chief Minister Naveen Patnaik's party.
"The party has decided that Ashwini Baishnab will be the Bharatiya Janata Party's candidate for the upcoming bypolls to the Rajya Sabha from Odisha," the BJP said.
Minutes later, Patnaik told reporters in the state that Prime Minister Narendra Modi and BJP president Amit Shah had spoken to him and his party will back Baishnab.
With 112 members in the 146-seat state assembly, the BJD was in a position to win the bypolls to all three seats. The BJP has 23 seats.
Baishnab, an IAS officer who had served as private secretary to the then prime minister Atal Bihari Vajpayee, enjoyed cordial relations with Patnaik, whose party was a BJP ally during the Vajpayee era. Patnaik had also served as a minister in that government before he became the state's chief minister in 2000.