He is Mr Vajpayee's main rival in this religiously charged campaign for a Lucknow parliamentary seat. Voting starts today, the second round of the Indian elections.
"He said that as an elder brother (an Indian term of respect) I should bless him. And so I did," said Mr Vajpayee, chuckling that his main challenger, and a Muslim at that, should seek blessings from the leader of a right- wing Hindu party that most Indian Muslims have learned to fear.
That is because Mr Vajpayee has a reputation as a bright, decent man, a liberal who keeps his distance from the Hindu extremists within the BJP who wave tridents and saffron-coloured flags and shout anti-Muslim slogans.
He is an accomplished ex-foreign minister with a natural, populist manner (he can sling himself on to a rope charpoy bed at a roadside tea-stand and have the crowd belly-laughing at his jokes). The only jab which his opponents can make against him is that because of his broad-mindedness, Mr Vajpayee may be "the right man in the wrong party".
When Hindu extremists tore down a 16th-century Mogul mosque in Ayodhya, igniting communal riots across the country, Mr Vajpayee is said to have wept and called it "an outrage", while other BJP leaders rejoiced.
But the "wrong party" may at last be right for Mr Vajpayee. The BJP seems to be as elastic as Hinduism, a faith which embraces a multitude of gods and seemingly conflicting practices. Having sensed that Indians have lost the stomach for the BJP's strident Hinduism after the 1992 riots and killings, the party is - apparently - transforming itself into Mr Vajpayee's more moderate image.
Mr Vajpayee may still appear at campaign rallies flanked by actors dressed up as heroes from the Ramayana epic, but his speeches are not about destroying more Muslim places of worship but about matters that are closer to the common Indian: government corruption, over-population, and how economic reforms have failed to reach the countryside.
Self-possessed and with a wry smile, Mr Vajpayee looks equally at ease whether he's greeting a visiting head of state or riding a bullock cart along the dusty campaign trail in Uttar Pradesh state.
In the likely event that neither the BJP nor the ruling Congress Party wins a clear majority, Mr Vajpayee is better placed than his combative companions in the BJP triumvirate - LK Advani and Murli Manohar Joshi - to strike a deal with coalition partners.
When votes are finally tallied, on 10 May, after the third stage of elections, forecasts indicate that the BJP may emerge as the largest party, with about 200 of the 543 parliamentary seats.
"We have no thoughts of forming a coalition, but if we fall short we'll seek support from the regional parties," said Mr Vajpayee, 69. At rallies, the grim-faced Black Cat commandos assigned to protect Mr Vajpayee seem genuinely to like him; they even grin at his jokes.
Mr Vajpayee insists he never wanted to be the BJP's candidate for prime minister, that he is a born loner, a misfit.
But shortly before elections, the party president, Mr Advani, was snared in a corruption scandal that was devised by the Prime Minister, Narasimha Rao, to cripple his enemies.
Mr Vajpayee was clean and he stepped into Mr Advani's place. Electorally, it was probably a stroke of good fortune for the BJP that Mr Vajpayee got the job. Even Mr Advani admitted that he lacks his replacement's "mass leader" qualities.
But even if Mr Vajpayee has gained the respect of his film- star rival and other Muslims and moderates, he has failed to dispel the suspicion that many Indians feel towards his party. They say that the religious extremists within the BJP may not let Mr Vajpayee stray too far into the centre.
The BJP manifesto pledges to expand India's nuclear status, which will speed up its atomic arms race with its Muslim neighbour, Pakistan. Nor is there much chance of India signing nuclear-disarmament treaties under the BJP. "We need nuclear weapons to protect India," Mr Vajpayee insisted. "We want to live in a nuclear-free world, but India cannot go along with this nuclear apartheid in which some nations have the bomb and others don't."
If elected, the BJP has said it will take a firmer stand against Muslim insurgents in Kashmir, though it is difficult to imagine how much tougher it could get: during this six-year revolt more than 20,000 Kashmiris have been killed by Indian security forces, human-rights monitors said. The BJP also vows to change the constitution, stripping away the special status held by religious and linguistic minorities.
Mr Vajpayee may also be under pressure from BJP traditionalists who want to shut the door on some multi-national companies, only recently allowed into India.
The BJP insists Indian values are being eroded by consumerism and loose western morality seen on imported Hollywood films and on Rupert Murdoch's satellite television beaming down to India.