A major global IT outage forced British Airways to cancel all its flights from Heathrow and Gatwick airports in London on Saturday, 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.
Travelers remained stranded at UK airports due to the outabe.
British Airways apologised in a statement for what it called an 'IT systems outage' and said it was working to resolve the problem.
It said in a tweet that the problem is global. Passengers at Heathrow Airport reported long lines at check-in and flight delays.
One posted a picture on Twitter of BA staff writing gate numbers on a white board.
"We've tried all of the self-check-in machines. None were working, apart from one," said Terry Page, booked on a flight to Texas.
We apologise for the current IT systems outage. We are working to resolve the problem as quickly as possible.— British Airways (@British_Airways) May 27, 2017
"There was a huge queue for it and it later transpired that it didn't actually work, but you didn't discover that until you got to the front."
The problem comes on a holiday weekend, when thousands of Britens are travelling.