The two rivals have attacked each other in their speeches on the campaign trail recently.
Narendra Modi and Rahul Gandhi are both addressing large gatherings today on a politically-charged Sunday that will see a battle of rallies between the BJP's presumptive Prime Minister and the man many expect to be the Congress' pick for the post if the party wins a third straight term in next year's general elections.
Mr Modi came to the Gandhi Maidan in Patna, Bihar despite a series of low intensity blasts in and around the venue.
This is the first time this election season that Mr Gandhi and Mr Modi are addressing rallies on the same day. Mr Gandhi will campaign in the Mangolpuri area of Delhi, which votes for a new assembly on December 4.
Both leaders have attacked each other in their many speeches on the campaign trail recently. Mr Modi has been more direct, calling Mr Gandhi "Shahzada" (prince) in recent speeches and rebutting him point by point on issues that the Congress number 2 has raised.
On Friday, Mr Modi targeted Mr Gandhi for alleging that young Muslim men whose families were affected in the communal riots in Muzaffarnagar in Uttar Pradesh last month had been contacted by Pakistani agencies.
Mr Gandhi has avoided naming Mr Modi, but has accused his party, the BJP, of practicing the "politics of hatred" and instigating communal violence in places like Muzaffarnagar. The Congress accuses Mr Modi of being a divisive leader and alleges that he did not do enough to prevent the riots of 2002 in Gujarat in which hundreds of people, mostly Muslims were killed.
It is the Congress vice-president's first rally in Delhi, where his party is hoping for a fourth straight stint in government. Chief Minister Sheila Dikshit will share stage with Mr Gandhi.
Mr Modi will be in Bihar today for his Hunkar rally only months after the state's Chief Minister Nitish Kumar of the Janata Dal United dumped the BJP, provoked by the prospect of the party naming the Gujarat Chief Minister its candidate for prime minister. The BJP did just that three months later.
For a chafing Bihar BJP, Mr Modi's rally is a matter of prestige and it has pulled out all stops to mobilise massive crowds in a show of strength. (
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