Some political observers have attributed the delay to internal differences within the party, which is being led by prime ministerial candidate Narendra Modi. (Track Live Updates)
"The main reason (for the delay) is that almost every senior leader who was made part of the manifesto drafting committee is fighting the election, and has been in his or her respective constituency, making it difficult to devote time to the document," a BJP leader told news agency AFP on condition of anonymity on Thursday.
Opinion polls say Mr Modi, the 64-year-old chief minister of Gujarat is the frontrunner for the country's top job. He is running on his credentials as a hands-on leader and economic reformer. (NDTV's Opinion Poll)
"A party and leader which claims great administrative and managerial competence is unable to release its manifesto in time," Priyanka Chaturvedi, spokeswoman for the ruling Congress party, tweeted on Thursday.
"Why is BJP unable to produce even a manifesto on time?" she added.
The mammoth nine-phase election starts on April 7 and concludes on May 12, with counting on May 16. (Elections schedule)
The ruling Congress party released its manifesto on March 26, pledging to create millions of jobs and new social schemes if it is voted back into power for a third consecutive term.