Gandhi's latest salvo came following French website Mediapart on Wednesday reporting that Reliance Defence was given to Dassault Aviation, makers of the Rafale jets, as an "obligatory" offset partner for the deal announced by Modi in April 2015.
"The reality is the prime minister is corrupt. The prime minister of India is a corrupt man," he said. Modi came to power on the promise of fighting corruption, the Congress leader said, adding that he wanted to tell the youth of the country that the prime minister was involved in corruption.
Rebutting Gandhi's allegations, the BJP accused him of belittling national security and spreading lies.
"People of this country do not want a clown prince to play with the national security. His press conference was full of lies and deception which he is using to build his political career. This will not happen," BJP spokesperson Sambit Patra said.
Patra dared Gandhi to produce evidence to prove his allegations that Hollande had called Modi corrupt.
The Congress president did not provide any evidence to back his allegations against the prime minister.
Rejecting the allegations, Patra said the BJP stands with the truth and accused Gandhi of making a mockery of national security. He also said the Indian Air Chief has recently described the purchase of the fighter aircraft as a "game-changer".
The BJP leader further said the Supreme Court has also dismissed a PIL (public interest litigation) that had questioned the aircraft's price and sought the deal cancelled.
"He (Gandhi) still has the audacity to hold a press conference and lie through his teeth. This is shamelessness," the BJP spokesperson said.
The political slugfest over the controversial multi-billion dollar Rafale deal has intensified in the wake of another French report published by 'Mediaprt' on Wednesday. Citing an internal report of Dassault Aviation, French publication 'Mediapart', in yet another investigative report, claimed the makers of Rafale jets had considered picking Reliance Defence as the offset partner in India “imperative and mandatory” to bag the contract.
Dassault Aviation, however, said in a statement that it has "freely chosen to make a partnership with India's Reliance Group".
Last month, Mediapart quoted former French president Francois Hollande as saying that France was given "no choice" on selection of the Indian partner for Dassault and the Indian government proposed the name of the Indian company to partner with the French aerospace giant.
The report triggered a massive political row with Congress escalating its attack on the government and the government firmly rejecting the charges.