The founder of budget carrier Easyjet Sir Stelios Haji-Ioannu has launched a libel claim against fellow industry operator Michael O'Leary, the chief executive of Ryanair.
Sir Stelios' case centres on an advert that he claims depicts him as a Pinocchio-style character with a long nose.
In a statement, the entrepreneur said he has begun legal proceedings in a bid to protect his reputation from implications that he is dishonest.
He remarked: "With this advert he went too far and I am obliged to draw the line here. This is a libel action about my own reputation as an individual, not about comparing the two airlines."
Sir Stelios went on to reveal that he is seeking "substantial damages" from the defendant.
As well as his endeavours with easyJet, the businessman runs the Stelios Philanthropic Foundation, which serves to promote education, entrepreneurship and the environment and has operations in the UK, Monaco, Greece and Cyprus.