Willie Walsh, the boss of British Airways’ parent IAG, has said he was pleased with how the airline handled last weekend’s crisis meltdown and insisted the problem was not to do with its IT.

Speaking in public for the first time since a power outage left 75,000 passengers stranded at airports, Walsh praised the way the carrier’s management headed by chief executive Alex Cruz dealt with the situation.

“I think the team under the leadership of Alex Cruz has done everything possible to get it back to flying a full schedule as quickly as possible,” he said.

“We know the cause of the problem. It was not about IT. The problem was caused by the failure of electricity power to the IT systems.

“We understand what happened but are investigating why and that will take some time.”

Walsh added the airline would ensure all passengers affected by the problems are satisfied with the resolution offered by the airline. Estimates of the cost to BA range from £75 million to £120 million.