Senior members of the Union Cabinet, chief ministers of BJP-ruled states and members of Parliament are among others to attend the meeting.
The agenda for the crucial Uttar Pradesh assembly is likely to be decided in the meeting being held in Allahabad.
Elaborate security arrangements have been put in place in view of the BJP's meeting.
The elite Special Protection Group (SPG), responsible for the Prime Minister's security, arrived in Allahabad on Thursday and has been busy reviewing security arrangements at the Kayastha Pathshala sports ground where the meeting will be held under a gigantic air-conditioned marquee, and the Parade Ground near the holy Sangam where a public rally will be held on Monday.
(With inputs from agency)