The civil aviation ministry has expressed reservations over the leasing of six major airports across the country to Adani Enterprises for operations, having informed a Rajya Sabha committee that “mandatory consultations” with states were not held before Centre reached the decision.

According to a media report, the civil aviation ministry informed a Rajya Sabha committee about due process not being followed on Dec 27 and Dec 28 last year. The need for a response by the civil aviation ministry on the matter was necessitated by a petition from a Kolkata-based resident Saptarishi Deb to Rajya Sabha, in which he had sought details of the agreement between Centre and Adani Enterprises.

Six airports- Lucknow, Thiruvananthapuram, Guwahati, Mangalore, Jaipur and Ahmedabad- were leased out by Centre to the business conglomerate under the PPP mode.

It surfaced last month that the Adanis had emerged as the highest bidder for Ahmedabad, Jaipur, Mangalore, Trivandrum and Lucknow airports. The Narendra Modi government had invited bids from private players to operate the airports for 50 years.

However, the deal has become already mired in controversy. Earlier this week, senior Communist Party of India-Marxist CPI (M) leader Kodiyeri Balakrishnan demanded a probe into how Adani Enterprises won the bid to operate five international airports, including Thiruvananthapuram.

Balakrishnan, the party's Kerala state Secretary, told the media in Thiruvananthapuram that it was quite strange that the group was able to win the rights to all the five airports.

"It is true that this was given through a tender and that's why we are doubtful if the tendering process was fool-proof... how come Adani won in all the five. We demand that a complete probe should be announced as this is nothing but a rip-off," he said.