British Airways delays and cancellations that have left a reported 15,000 passengers grounded today are the result of an IT systems failure that has resulted in the cancellation of over 80 flights.

The issue (we have yet to obtain exact details) comes just three days after the company managed to avoid strike action that would have disrupted travel at the peak of the holiday season.

A major IT outage in 2017 cost the airline as estimated £58 million and led to legal action between BA and managed services provider CBRE. The CEO of BA’s parent company IAG blamed that issue on a CBRE technician inadvertently turning off the power supplying one of BA’s data centres.

An internal email from within the IAG leaked to press in June of 2017 said: “This resulted in the total immediate loss of power to the facility, bypassing the backup generators and batteries… After a few minutes of this shutdown, it was turned back on in an unplanned and uncontrolled fashion, which created physical damage to the systems and significantly exacerbated the problem.

British Airways said on its website: “We are very sorry to our customers for the disruption to their travel plans. We are working as quickly as possible to resolve a systems issue which has resulted in some short-haul cancellations and delays from London airports.”

The airline is advising customers to check the latest flight information before coming to the airport. “We are offering customers booked on short-haul services departing from Heathrow, Gatwick and London City today, the opportunity to rebook to another day. ”

The news comes a day after a BA plane was forced to land when its cabin filled with smoke. Passengers had to use emergency exits after the issue on BA422 which departed London Heathrow at 15:10 BST on Monday and landed in Valencia. Passengers complained of no communication from staff.

The issue is the latest IT woe suffered by BA, which faces the prospect of a £183 million fine by the ICO after failing to secure the payment details of half-a-million customers in 2018. The Information Commissioner hit out at “poor security arrangements” last month when announcing the planned fine.

IT providers to BA declined to comment this morning.

The company has some 500 data cabinets spread across six halls in two different sites near its Heathrow Waterside HQ.