According to initial investigations into the problem by Nats, its systems, both primary and the back-ups, responded to the data by suspending automatic processing to ensure no incorrect safety-related information could be presented to an air traffic controller or impact the rest of the air traffic system.

Nats chief executive Martin Rolfe, who apologised for the situation, said there were no indications this was a cyber-attack. "We have well established procedures, overseen by the CAA, to investigate incidents," he added.

"We are already working closely with them to provide a preliminary report to the secretary of state for transport on Monday. The conclusions of this report will be made public."

Nats’ systems have several levels of backup which allow the company to manage around two million flights per year.

"Very occasionally technical issues occur that are complex and take longer to resolve," Rolfe explained. "In the event of such an issue our systems are designed to isolate the problem and prioritise continued safe air traffic control."