BBC News
Holidaymakers heading to and from the UK will face disruption for days after an air traffic fault caused chaos, the transport secretary has warned.
Hundreds of flights were cancelled or delayed due to the technical glitch with the UK's air traffic system, leaving thousands of people stranded.
National Air Traffic Services (Nats) confirmed the fault just after midday on Monday, before it announced at 15:15 BST that it had identified and remedied the issue.
But it said it would "take some time for flights to return to normal" - as it launched an investigation into what went wrong.
The government is confident there was no cyber attack, Transport Secretary Mr Harper told BBC Radio 4's Today programme on Tuesday morning - but he admitted the timing "was not at all helpful for people".