Customers and frequent flyers with British Airways (BA) as a third day of disruption seems imminent for the British airline.
According to RTÉ, both Heathrow and Gatwick airports have warned travellers flying with British Airways - saying they should double-check the status of their flights before going to the airports - as chaotic scenes have unfolded there all weekend.
The situation has grown more urgent as today is a bank holiday in the UK.
It's been reported that travellers spent the night sleeping on yoga mats on terminal floors on Saturday night, following BA's cancellation of all flights leaving London.
The IT crises affected dozens of international flights and even left those lucky enough to have caught a flight without their luggage.
The airline has been slated previously for cutting British IT staff and contracting the work to India back in 2016.
Mick Rix, national officer for aviation at the union, said at the weekend:
"We can only feel genuinely sorry for the tens of thousands of passengers who are stranded at airports and face having their travel plans and holidays ruined.
"This could have all been avoided. In 2016 BA made hundreds of dedicated and loyal IT staff redundant and outsourced the work to India.
"BA have made substantial profits for a number of years, and many viewed the company's actions as just plain greedy."
However, hope is prevailing. A spokeswoman for the airline said:
"We operated a full schedule at Gatwick on Sunday. At Heathrow, we operated virtually all our scheduled long-haul flights, though the knock-on effects of Saturday's disruption resulted in a reduced short-haul programme.''
"As our IT systems move closer to full operational capacity, we will again run a full schedule at Gatwick on Monday and intend to operate a full long-haul schedule and a high proportion of our short-haul programme at Heathrow.
"We apologise again to customers for the frustration and inconvenience they are experiencing and thank them for their continued patience."