Communist Party of India (Marxist) leader Kodiyeri Balakrishnan on Wednesday sought an investigation into how Adani Enterprises won a bid to operate five international airports, including Thiruvananthapuram, IANS reported. Last month, the Adani Group won a bid to operate airports in Ahmedabad, Thiruvananthapuram, Lucknow, Mangaluru and Jaipur.

“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?” asked the party’s Kerala state secretary. “We demand that a complete probe should be announced as this is nothing but a rip-off.”

Kodiyeri said the party will launch a strong protest against the “high-handed corrupt deal” and requested the Congress-led United Democratic Front as well as the Bharatiya Janata Party to join them. “This has taken place just before the upcoming polls and, hence, it is not a proper tendering process, it’s a corrupt deal,” he said.

An unidentified Airports Authority of India official earlier said the Adani group won the contracts because it was the highest bidder in the “per-passenger fee” category. In the bid for the Thiruvananthapuram airport, the Kerala State Industrial Development Corporation had bid Rs 165 against the Adani group’s Rs 168, making it the second highest bidder in the process.

Kodiyeri accused Congress MP from Thiruvananthapuram, Shashi Tharoor, of playing a role in ensuring that Adani won the bid for the airport.

Kerala Chief Minister Pinarayi Vijayan had also raised doubts about the transparency of the allotment process. “One business group winning all five bids is quite unusual,” he had said. “It casts doubts on the bidding process itself. Was it [bidding] a drama to hand over the rights to Adani who is closer to [the] prime minister? Adani might be knowing Modi well, but he has no experience in running airports.”

Vijayan had written to Modi last week and asked him not to hand over the Thiruvananthapuram airport contract to Adani. The chief minister also pointed out that the Kerala State Industrial Development Corporation has already moved the High Court challenging the tender process through which Adani was chosen as the winner.