EasyJet founder and largest shareholder Sir Stelios Haji-Ioannou has vowed to oppose management plans to buy 135 Airbus aircraft valued at around $12 billion.

He cites a lack of transparency over the deal, saying: “It is my firm opinion that this is a good deal for Airbus and a bad deal for easyJet shareholders.”

Shareholders will vote on the transaction July 11, which Stelios said he expects to be approved. He owns just under 37% in the carrier.

“I am not against replacing aircraft that have reached the end of their economic life,” he said.

“However I am against buying aircraft that are three times more expensive than the ones I bought with my own money in the early 2000s.

“Nor am I against directors trying to engineer some top line growth – but not at the expense of the profit margin.

“I am not against planning ahead for the next 4-5 years but I see no reason why this set of directors need to commit the company for the next nine years (or even longer if options are taken into account). Remember – none of these directors will be around in nine years time.”

Some 85 of the 135 aircraft will replace older aircraft, with the remainder helping to boost seat capacity by between 3 and 5% annually, the carrier said last month.

EasyJet has yet to respond to the comments made by Sir Stelios in an open letter to shareholders.