The Congress, which has alleged corruption and favouritism in the contract and accused the prime minister for it, also dubbed the fighter jet deal "opaque and flawed".
Accusing Prime Minister Narendra Modi of acting as a "frontman for corporate friends", the Congress on Monday took objection to Defence Minister Nirmala Sitharaman describing the opposition's questions on the Rafale deal as borne out of "corporate rivalry".
The party's senior spokesperson Anand Sharma said Sitharaman, who spoke for the deal in the Lok Sabha, was reduced to being an "apologist defending the indefensible".
The Congress, which has alleged corruption and favouritism in the contract and accused the prime minister for it, also dubbed the fighter jet deal "opaque and flawed".
The government has denied the charges levelled by the Congress and said the deal is clean, without any corruption or middlemen.
Claims by the government and the BJP that the Rafale deal is transparent and cut out middlemen are "laughable and ridiculous", Sharma said.
"The fact is it was opaque and flawed. surely no middlemen... good. But what when Pradhan Mantri ji acts as a frontman for corporate friends?
"Why has the PM not personally denied former French President François Hollande's statement? Any answers?" he asked on Twitter.
The opposition, he said, had raised fundamental questions on the Rafale jet acquisition.
"These include compromising national security, hurting national manufacturing and denial of technology to HAL and loss to national exchequer.
"Defence Minister terming it as corporate lobbying is objectionable. Sad to see defence ministry misused to cover up and minister reduced to being an apologist defending the indefensible," Sharma tweeted.
PTI