The Congress president said it is time the finance minister and the prime minister call for a Joint Parliamentary Committee (JPC) probe for an "uncorrupted truth" to come out in the Rafale deal.
Congress senior spokesperson Anand Sharma accused the prime minister of having "betrayed" the country and demanded that he respond to the charges made in connection with the deal instead of fielding his ministers.
"My direct charge is that the prime minister violated the oath of confidentiality. Only he could have told Anil Ambani that HAL will be out and he will strike a deal to buy 36 jets and you (Ambani) go and talk to Dassault Aviation (the makers of Rafale jet)," Sharma told reporters at a news conference.
"Why is the prime minister, who speaks on every issue, quiet. The one who is supposed to speak is quiet (maun vratt). When the charges are directly against him, no one can speak on his behalf," the deputy leader of opposition in Rajya Sabha said.
Attacking the government on the issue, Gandhi accused Jaitley of having the ability to spin "2 truths or lies" with "fake self-righteousness" and "indignation to defend the indefensible".
"Mr Jetlie's speciality is his ability to spin '2 truths', or lies, with fake self righteousness and indignation to defend the indefensible. It's high time he, the RM and our PM stop lying and call a JPC to establish the full, uncorrupted truth about the Rafale Scam (sic)," Gandhi tweeted.
He also tagged a media report highlighting how former French president Francois Hollande's charges have hit the Modi government on the Rafale issue.
In a press conference, Sharma threatened of criminal cases after a thorough probe into the entire deal if the Congress came to power, claiming that Modi will not be the prime minister in 2019 election.
Sharma said the question is how could have the Government of France or former French President Francois Hollande or the Dassault company decided that HAL will be out.
The deputy leader of Congress in the Rajya Sabha said, it is clear that the finance minister, defence minister, law minister have joined in a competition "to lie to defend our prime minister who is directly complicit" and there cannot be any other explanation.
"My message to Shri Narendra Modi is very clear. He cannot escape and all those within the country and outside will try to cover-up this scam of the century will stand exposed," he said.
Sharma said since the Government of France and its former president had no say, why is the Modi government contesting and insulting the former French president.
The Congress leader accused the prime minister of taking an "unauthorised action" without a mandate from the Cabinet Committee on Security in ordering the 36 aircraft off the shelf.
"So, who is to answer this question, nobody else, but Shri Narendra Modi," he said, demanding answers from him.
He also said that since the earlier contract was live and the global tender was alive, how could he have unilaterally cancelled the same.
The Rafale controversy took a turn last week after former French president Hollande claimed that the Indian government proposed Reliance Defence's name as the offset partner for Dassault Aviation.
In response, the French government said it was in no manner involved in the choice of Indian industrial partners for the Rafale deal, asserting that French firms have the full freedom to select Indian companies for the contract.
Jaitley earlier defended the prime minister on the Rafale issue, saying the French government and Dassault Aviation have categorically denied the correctness of the former president's first statement.
He said the French government has stated that the decision with regard to the offset contracts of Dassault Aviation are taken by the company and not the government.
The Reliance group has rejected charges against it made by the Congress and said the government was in no way involved in securing its offset contract with Dassault Aviation.
Elaborating his charges, Sharma said in 2007, a Request for Proposal (RFP) was published for a global tender. In 2012, the Rafale jet was selected as L1 (lowest bidder) and Price Negotiations Committee and CNC (Contract Negotiating Committee) after conducting talks, had finalised the contract to buy 126 jets.
"The two governments had signed on the contract. Only the aspect of life cycle cost was pending. Even before Modi became the prime minister, this deal had been finalised. According to the annual report of Dassault Aviation, on March 13, 2014 it had signed a work share agreement with the HAL," Sharma said.
He further added that on March 25, 2014, Eric Trappier, the CEO of Dassault Aviation, had said in the presence of the then IAF chief and then HAL chairman that the two sides have finalised their contract and only the signing formality was left.
Prime Minister Modi had announced the procurement of 36 Rafale fighters after holding talks with then French president Hollande on April 10, 2015 in Paris.