A major global computer failure today forced British Airways to cancel all its flights from Heathrow and Gatwick airports in London, leaving thousands of travellers stranded as a workers' union blamed outsourcing to India for the "meltdown".
The carrier had earlier said flights will be cancelled until 1800 local time but has now confirmed all its flights will remain grounded at both airports throughout the day.
The GMB union said the "meltdown" could have been avoided if BA hadn't made hundreds of IT staff redundant and outsourced their jobs to India at the end of last year.
"This could have all been avoided. In 2016 BA made hundreds of dedicated and loyal IT staff redundant and outsourced the work to India," said Mick Rix, national officer for aviation at GMB.
"BA have made substantial profits for a number of years, and many viewed the company's actions as just plain greedy," he said.
The move in 2016 had sparked protests and outrage from members of the union.
At the time, a BA spokesperson had said: "A contract has been signed with the TCS to be the supplier of some IT activities in British Airways, and British Airways has been in consultation with those IT staff affected, about 200.
"British Airways employs around 35,000 people in the UK, providing high-skilled and well-paid jobs. It hires 1,000 people a year and has a strong apprenticeship programme."
The TCS is yet to comment on the matter.
Earlier today, BA apologised for the "global system outage" and said it was "working to resolve the problem as quickly as possible".
"A major IT system failure is causing very severe disruption to our flight operations worldwide," the airline said.
The chaos comes on what is a Bank Holiday weekend in the UK, involving thousands of additional journeys as people make use of the long weekend due to an annual holiday on Monday.
Heathrow Airport said it was "working closely" with BA to solve the issue. There is nothing to suggest the problems are a result of a cyber attack at this stage.
It is not known how many flights are affected but passengers have reported issues with flights to and from Heathrow, Gatwick and Belfast.
BA aircraft landing at Heathrow are unable to park up as outbound aircraft cannot vacate the gates, which has resulted in passengers being stuck on aircraft.
Heathrow has advised passengers to check the status of their flight before travelling to the airport.
All affected passengers will be offered the option of rescheduling or a refund.