The Congress chief also described Defence Minister Nirmala Sitharaman's 3-day trip to France as part of a 'huge cover-up' by the government.
A report by a French publication on selection of Indian partner in the Rafale deal triggered a fresh round of fierce attack and counter-attack between the Congress and the Bharatiya Janata Party with Rahul Gandhi alleging Prime Minister Narendra Modi was 'corrupt' and demanding a probe into his role in the jet procurement.
Strongly countering Gandhi's charges, the BJP accused the Congress chief of 'lying through his teeth shamelessly' and indulging in 'politics of misinformation' to build his political career.
Calling him a 'clown prince', the BJP alleged that the Congress president belonged to a 'family of middlemen' with his father and former prime minister Rajiv Gandhi being 'officially a middleman' in a defence deal.
The political offensive came a day after some reports, citing French publication Mediapart, said an internal document of Dassault Aviation showed that the manufacturer of Rafale had to choose Ambani's firm Reliance Defence as its offset partner in India as a trade-off for getting the deal.
On a visit to France, Defence Minister Nirmala Sitharaman said in Paris that offset obligations for the deal is mandatory but not the names of the companies.
In a statement, Dassault Aviation also said it has 'freely chosen to make a partnership with Reliance Group', as it rejected the report by French publication Mediapart.
The latest report followed former French President Francois Hollande's comments last month 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.
Hollande was French president when the Rafale deal was sealed.
At a press conference, Gandhi also described Defence Minister Nirmala Sitharaman's ongoing three-day visit to France as part of a 'great cover-up'.
"The reality is that the prime minister is corrupt. The prime minister of India is a corrupt person, but he came to power on the promise of fighting corruption," Gandhi told reporters.
"... in the Rafale contract. the prime minister has indulged in clear-cut corruption and there should be an investigation on it," he said.
Questioning Modi's silence on the issue, Gandhi said, "It is clear there is pressure. If he is unable to respond, he should resign."
The Congress president, however, did not provide any evidence to back his allegations against the prime minister.
Rejecting his allegations, BJP spokesperson Sambit Patra hours later alleged at his press conference that the Congress leader comes from 'a family of middlemen' and his his father and former prime minister Rajiv Gandhi was 'officially a middleman' in a defence deal.
While the Opposition has been attacking the Modi dispensation over the multi-billion dollar Rafale deal, the government has been maintaining it had no role in Dassault's choice of Reliance Defence.
Defence Ministry sources said Sitharaman's visit to Paris was pre-scheduled and it has nothing to do with the Rafale controversy.
"Why has suddenly the defence minister rushed to France? What is the emergency?" Gandhi asked and claimed the purpose of the visit was 'to put pressure on Dassault, to silence them and do a cover up'.
"This is the logic," the Congress chief said.
Gandhi claimed a senior Dassault executive has said India's prime minister pushed the contract and now both Hollande and Dassault are saying the Indian prime minister has said that 'without this compensation, this deal cannot be done'.
The Congress chief reiterated his charge that Modi is Ambani's "chowkidaar', and not of the country.
Rebutting the charges, Patra counter-alleged that it was Gandhi family that made money from every defence deal till 2014 and Rahul Gandhi has not been able to come out of that mindset.
Patra said the BJP stands with the truth and accused Gandhi of making a mockery of national security. He also said the Indian Air Force Chief has recently described the purchase of the fighter aircraft as a 'game-changer'.
Patra also read out from a statement of Dassault Aviation, manufacturer of Rafale fighter aircraft, to claim that Gandhi inserted 'Reliance' deliberately where the firm has spoken about its commitment to offset purchase from India.
The BJP leader further said the Supreme Court has also dismissed a PIL that had questioned the aircraft's price and sought the deal cancelled.
He said the people will decide whether to believe Gandhi or the Supreme Court and the Air Force Chief.
Shatrughan attacks government on Rafale deal
Dissident BJP MP Shatrughan Sinha on Thursday said people want answers from the government on the Rafale deal and 'ignoring' the questions being raised over the agreement would not do.
His remarks come amid relentless opposition attack on the government over the deal.
Addressing a gathering in Lucknow on the occasion of the birth anniversary of Loknayak Jayaprakash Narayan, who gave the clarion call of 'Sampoorna Kranti' (complete revolution), Sinha asked why PSU Hindustan Aeronautics Limited was 'sidelined' in favour of a private firm as an offset Indian partner of Dassault Aviation for manufacturing the fighter aircraft.
"The public want an answer on the Rafale deal. You have to speak up, and mere ignoring it will not do. Why was HAL which had the experience of manufacturing MiGs and Sukhoi sidelined and a 10-day-old company with (virtually) zero balance and zero experience was given the job," the BJP MP said, flanked by former party leader Yashwant Sinha and Samajwadi Party president Akhilesh Yadav.
He said power should be a medium to serve the people 'not to reap dividends'.
He defended his remarks attacking the government, saying, "If speaking the truth is considered as mutiny, then I am a mutineer."
"Making hollow promises, giving speeches and indulging in rhetoric will not work any more. Party is always bigger than a person and the country is bigger than the party. If I am talking in the interest of the country, then what is wrong in it?"
Sinha said Jayaprakash Narayan was his inspiration to join politics.