"The construction of the Ram Temple is an instrument to unite the country," Modi said in a message published on newspaper front pages ahead of a spectacle that will be watched by millions of Indians at home and abroad.
India's Hindus say the site is the birthplace of Lord Ram, and was holy to them long before Muslim Mughals razed a temple at the spot to build the Babri Masjid, or mosque, in 1528.
Nearly 8,000 people are expected to attend the invitation-only ceremony, from top business leaders to movie stars and sportspersons.
More than 10,000 police personnel have fanned out across the city of 3 million people to provide security and keep out gatecrashers.
The temple opens to the public on Tuesday and its management expects at least 100,000 visitors a day for the first few months.
Persons:
Saurabh Sharma, Rajesh AYODHYA, Lord Ram, Narenda, Modi, Pratap Bhanu Mehta, YP Rajesh, Clarence Fernandez
Organizations:
Bharatiya Janata Party, BJP, Supreme Court, Indian Express, YP
Locations:
India, Ayodhya, Ram