This week EasyJet admitted that its passenger growth in the second half of this year would be about 21% - compared with Ryanair's expected 60% growth - and is looking at bringing its founder and former figurehead back into the limelight.
Haji-Ioannou has not appeared in an EasyJet ad for 18 months, after announcing he was stepping down from the board to concentrate on his other EasyGroup ventures.
"Stelios represents some very positive values. He was the man who democratised flying in Britain and there's a great sense of empathy among consumers," said EasyJet sales and marketing director Mike Cooper.
He added: "We've confused our City audiences with our consumer audiences. While Stelios has stepped down from managing EasyJet, he still appeals to the flying public."
Haji-Ioannou told Marketing that he did not know whether he would return to the ads and was waiting for the matter to be formally raised.
Ryanair has recently embarked on an aggressive campaign, claiming lower fares and superior punctuality than EasyJet.
For its part, EasyJet has fought back with its own heavyweight outdoor ad campaign.
However, a recent execution showing a woman's bra-clad breasts with the line "Discover weapons of mass distraction" prompted 168 complaints to the Advertising Standards Authority.
Separately, it has emerged that Haji-Ioannou will use part of the £17m he raised by selling EasyJet shares last week to hire a chief executive for his EasyCar business.
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