Prabhu, who was Power Minister in the Atal Behari Vajpayee-led previous NDA government, received the party's primary membership in the morning and was welcomed by senior party leaders.
The 61-year-old banker-politician was a Shiv Sena leader and joins at a time when there is simmering tension between the Sena and the BJP amid talk that Uddhav Thackeray will pull his party out of the government at the Centre and play the role of opposition in Maharashtra.
During Vajpayee's tenure from 1998 to 2004, Prabhu was Industry Minister, Minister of Environment and Forests, Minister of Fertilizers & Chemicals, Power, Heavy Industry and Public Enterprises.
Prabhu has represented the Rajapur Lok Sabha constituency in Konkan four times, from 1996 to 2009. He lost his seat in the 2009 general election. This is the same constituency which late Janata Party leader Madhu Dandavate had represented.
Prabhu's decision to call off his visit to Wharton School as a mark of protest against the cancellation of Modi's keynote address at the Wharton India Economic Forum 2013 won him accolades from BJP.