Without naming the ruling BJP, senior RSS functionary Suresh "Bhaiyyaji" Joshi sharply criticized the party and its government.
Trident-waving devotees clad in saffron filled the sprawling Ramlila Maidan grounds under tight security, warning Modi that they would not let up until the temple was sanctioned.
Causing a frenzy in a crowd of more than 200,000 people, Hindu seers made a series of fiery speeches laced with religious overtones to demand action paving the way for a temple in the northern town of Ayodhya.
The Vishwa Hindu Parishad (VHP) mobilised supporters from Noida, Ghaziabad, Meerut and Delhi for a rally at the Ramlila Maidan here on Sunday to press its demand for the construction of a Ram temple at the site in Ayodhya where Hindutva mobs tore down the historic Babri Masjid on December 6, 1992.
The BJP was on the margins until the 1980s when its top leaders, including Modi, backed a growing movement for the construction of the Ram temple. "They are aware of the sentiments", he said.
"We are not begging for Ram temple but it is our right".
As several busloads of people brought in from the countryside alighted, VHP activists shouted slogans of 'Vande Mataram', 'Bharat Mata ki Jai' and 'Jai Shree Ram'.
Shah skipped any mention of the Ayodhya land dispute pending before the Supreme Court and asserted that a Ram temple should be built "immediately".
He accused the Congress of trying to create hurdles in the path of a temple and said Kapil Sibal had petitioned the Supreme Court to postpone the hearing of the Ayodhya title suit till the 2019 polls were over.
But as the dispute has remained unresolved for more than 25 years, right-wing groups are demanding that the Union government sidestep the courts and go ahead with the temple building.
Besides Joshi, VHP's president Vishnu Sadashiv Kokje and its global working president Alok Kumar will also address the rally, Bansal said, adding that various saints will also address the gathering.
The VHP had carried out a door-to-door campaign to make the rally a success. No traffic will be allowed on Ranjeet Singh Flyover (from Guru Nanak Chowk to Barakhambha Road), JLN Marg (from Rajghat to Delhi Gate), Chaman Lal Marg near VIP gate, the advisory said.
The VHP had approached President Ram Nath Kovind and state governors during previous phases of its temple campaign.
The timing of the "dharam sansad", or congregation of Hindu religious leaders, in the national capital comes just two days before the start of the month-long winter session of Parliament-the last full session before the general elections early next year. The final "Dharam Sansad" will be held on January 31 and February 1.