British Airways is facing calls to "automatically compensate" passengers who were caught up in the bank holiday chaos that left some 75,000 people stranded last weekend.
The airline has been urged by Consumer group Which? to automatically issue its statutory compensation to all affected passengers rather than wait for them to submit claims in a bid to "reduce the burden on passengers".
The call for action comes after thousands of people found themselves stuck when a reported "IT failure caused by a power surge" on Saturday May 27 grounded scores of flights and left services disrupted until Tuesday.
Doubts have been raised over BA's power problem claims after energy providers denied there had been a power surge leading to reports that the BA board is now set to demand an independent inquiry into the IT shutdown after its back-up systems also failed.
Under EU law passengers can claim compensation for travel disruption, worth up to 600 euro (£524) as well as expenses for items such as hotels, meals and phone calls.
Which? managing director of home product and services Alex Neill urged BA's chief executive Alex Cruz in a letter to issue this compensation immediately to "minimise additional stress and inconvenience" for customers.
He wrote: "As you will know, the rules around compensation in this sector are out of step with other markets, like energy and water, where compensation is automatically awarded to customers for severe disruption to, or complete absence of, service.
"Given the scale of the problem BA has experienced we strongly believe it is only right that you do more than the legal minimum. By simplifying the compensation process, you have an opportunity to minimise the additional stress and inconvenience you cause your customers and ensure they are not pushed into the arms of claims management companies, who will take a large part of the money they are owed."
BA apologised for the "difficulties and frustration customers faced" and made assurances they would honour compensation obligations.
A spokeswoman said: "We will fully honour our EU compensation obligations and have set up a link on the home page of our website to enable customers to submit their claims as quickly and conveniently as possible.
"We have no desire to be obstructive in any way and have put additional resources into our call centres to process claims as speedily as possible."