Congress President Rahul Gandhi on Tuesday accused Prime Minister Narendra Modi of treason and claimed he had acted as a middleman for industrialist Anil Ambani in the Rafale jet deal that India signed with France, PTI reported.

Quoting from an email written by an Airbus executive to a French official, Gandhi claimed that Ambani was aware of the Memorandum of Understanding before India and France signed it in 2015.

Citing a report in The Indian Express, Gandhi said that Ambani had met the then French Defence Minister Jean-Yves Le Drian days before the deal was signed during Modi’s visit to France in 2015. Modi had violated the Official Secrets Act by giving Ambani details about the deal that even then Defence Minister Manohar Parrikar was unaware of, Gandhi claimed.

He alleged that only Modi could have told Ambani about the deal in advance. “This is treason,” said Gandhi. “He [Modi] is doing what spies do.”

According to the news report, Ambani visited Paris in the last week of March 2015 and held a meeting with Le Drian and his top advisors, about a fortnight before Modi signed the deal. Ambani’s Reliance Group is the offset partner for Dassault Aviation, manufacturer of Rafale aircraft.

In a press statement, the Congress claimed Modi and Ambani were directly negotiating the deal as neither Parrikar nor the Ministry of External Affairs or the Cabinet was unaware of the agreement.

Gandhi also rejected the Comptroller and Auditor General report on the Rafale deal, describing it as the “Chowkidar Auditor General” report. The government is set to table the report in the Lok Sabha on Tuesday. The Congress on Sunday had urged Comptroller and Auditor General Rajiv Mehrishi to recuse himself from auditing the deal, alleging a conflict of interest. Mehrishi was the finance secretary when the deal was signed and was part of the negotiations.

Last week, a report in The Hindu alleged that the Prime Minister’s Office had conducted “parallel negotiations” with France in 2015 about the deal. The Ministry of Defence had reportedly objected to this development.

The central government had reportedly also waived critical provisions for anti-corruption penalties and overruled the recommendations from financial advisors for an escrow account for the Prime Minister’s Office days before signing the deal.

Gandhi had accused Modi and Defence Minister Nirmala Sitharaman of having lied to the country, and the Opposition had intensified its demand to hold a Joint Parliamentary Committee probe into the deal.