The video tweeted by the Congress has Dassault chief Eric Trappier speaking on March 25, 2015, in the presence of the Indian Air Force and HAL officers. Mr Trappier can be heard discussing responsibility sharing on the Rafale contract. "17 days later PM Modi gave the contract to Reliance," tweeted the Congress, demanding Defence Minister Nirmala Sitharaman's resignation for "lying to the nation".

On April 10, 2015, PM Modi announced the purchase of 36 Rafale jets at around Rs 60,000 crore after talks with then French president Francois Hollande.

The previous Congress-led UPA government had negotiated with Dassault for 126 Rafale jets under which 18 jets were to be supplied in a fly-away condition and 108 were to be manufactured in India along with HAL. However, the UPA could not seal the deal.

The opposition asked how HAL was out despite being part of the negotiations with Dassault until just before the PM's visit to France in April 2015. On April 8, then Foreign Secretary S Jaishankar also made it clear that HAL was very much on board.

Mr Jaishankar had said: "In terms of Rafale, my understanding is that there are discussions underway between the French company, our ministry of defence, the HAL, which is involved in this. These are very technical, detailed discussions. We do not mix up leadership level visits with deep details of ongoing defence contracts. This is on a different track. A leadership visit usually looks at big picture issues even in the security field."

In the new deal, Anil Ambani's rookie company Reliance Defence became Dassault's offset partner with no experience in the field. As part of the offset clause, Dassault has to ensure that business worth at least half the money -- Rs 30,000 -- is generated in India.

President Hollande dropped a bombshell last week as he said France had been given no choice on picking Anil Ambani's company as Dassault's offset partner in 2016. He made the comment while denying in an interview any conflict of interest with Reliance, which partly financed a film produced by his partner, Julie Gayet, in 2016.

Sources in Dassault have told NDTV that the group had been talking to Mukesh Ambani's Reliance, which had an interest in defence from 2012-2015. They started talking to the Anil Ambani Reliance when the business changed hands. Dassault says the joint venture with Reliance worked well as it was located next to an airport in Nagpur with taxiways.

Congress chief Rahul Gandhi attacked the government, saying: "An ex-president of France is calling him (the prime minister of India) a thief. It's a question of the dignity of the office of the prime minister."