India has vowed to stand firm on a multi-billion dollar deal to buy warplanes from France's Dassault Aviation, as the opposition Congress party yesterday called for an inquiry into allegations of wrongdoing.

Former French President Francois Hollande, who approved the deal when he was in office, triggered a political storm in India after he said the Indian government influenced the choice of a local partner in the deal.

New Delhi has denied the allegations, but opposition parties are gunning for Prime Minister Narendra Modi over the 2016 purchase of 36 Rafale planes estimated to be worth $8.7 billion, saying he overpaid for the planes and had not been transparent.

Congress' national spokesman Sanjay Jha said they would call for a joint parliamentary committee to investigate the deal, and organise public protests.

"We will take it to the people's court through protests and demonstrations as what is involved in this massive fraud is the taxpayers money," he told Reuters.

Finance Minister Arun Jaitley said on Sunday that the deal would proceed as planned.

"These jets will come to India. They will enhance the combat ability of the Indian Air Force," Jaitley told television news agency ANI, a Reuters affiliate.

In recent months, the opposition has questioned the government on the choice of billionaire Indian businessman Anil Ambani's Reliance Defence as Dassault's local partner instead of a state-run manufacturer with decades of experience.

On Friday, Hollande told French news service Mediapart that New Delhi had put pressure on Dassault to choose Reliance.

"We had no choice. We took the interlocutor that was given to us," Hollande was quoted as saying.