EasyJet founder Sir Stelios Haji-Ioannou has called on easyJet to improve its performance within 90 days or risk losing the use of the ‘easy’ brand name.


Stepping up the row over how the carrier is run, Sir Stelios, who has waged a high-profile war of words against former easyJet chief executive Any Harrison, instructed lawyers to write to the airline with the warning.


The letter gives the airline 90 days to bring its on-time performance in line with the highest standards in the industry or risk losing its license to use the easy brand.


Sir Stelios attacked Harrison in a statement issued on the easyGroup website.


He said: “It is regrettable that the obvious mismanagement by Harrison in the last six months of his tenure as CEO has led to such deterioration to the customer service


“I have been receiving many unsolicited complaints from members of the public and even easyJet pilots about the degree that the airline is short of crew to operate the flights it sold to its customers.


“Unless (chairman) Mike Rake and (new chief executive) Carolyn McCall do something to improve the situation for the sake of the travelling public, I am left with no option but to terminate the brand licence.”


His anger has been sparked by weekend reports of poor punctuality of easyJet flights from Gatwick and its refusal to publish on-time statistics.


The solicitor’s letter said the current punctuality rates are “completely unreasonable and contrary to the brand values which easyJet and easyGroup companies have built their reputation”.


This was causing “serious damage” to both the easyJet and other ‘easy’ brands and the goodwill associated with them built up over many years.


The letter said: “The goodwill associated with the ‘easy’ brand will be damaged in the minds of customers that experience such bad punctuality.”