A fault on UK Border Force computers, including automatic passport check-in desks, caused systems to crash late this evening, causing widespread chaos for passengers at airports such as Heathrow, Gatwick, Stansted and Birmingham.
Extra staff were drafted in to try and reduce the queues.
Passengers tweeted their frustration through the evening:
A Government spokesman said: "We apologise for any additional time this adds to passengers' journeys."
More top news
The father of 'Fast & Furious' star Paul Walker is suing Porsche over his son's death.
Investigating judge in Belgium charges man with murder and participation in the activities of a terrorist organisation: reports
Margaret Rigby spent £57,000 of her friend's money on luxury goods for herself, after gaining power of attorney