A BA spokesman said: "Customers are being checked in as normal after an earlier problem was resolved. We are sorry for the temporary check-in problems which caused some delays for our customers first thing this morning.

"This issue is now resolved and our staff are working flat out to help customers get away on their holidays."

The delays for passengers trying to leave the country this morning come as holidaymakers are being warned they face lengthy delays at European airports due to tightened border checks.