"Since Thursday, when Terminal 5 opened, we have made clear that the service we have provided has not been good enough. We apologise sincerely to our customers," said Willie Walsh, British Airways Chief Executive in a statement.

"The baggage system is now generally working better.  From time to time problems have developed that were not encountered during the extensive trials. These issues are being addressed as they arise by a team of engineers and IT specialists from BAA and BA.

"A backlog of undelivered bags has built up. This backlog is not affecting the day-to-day operation of the baggage system, and we are making every effort to reunite delayed bags with their owners.

"We have more than 400 volunteers from across the airline supporting this effort."

According to Walsh, "this work takes time as delayed bags must undergo enhanced levels of security screening. Much of this process has to be done manually because we have been unable to use the Terminal 5 baggage system to process these bags automatically."

Walsh apologized for the disruption and inconvenience caused to customers whose flights have been cancelled or whose bags have been delayed. "We will not rest until our service has been restored to the high standard customers rightly expect. We continue to work towards increasing the number of services in the days ahead.

"Both British Airways and BAA have invested an enormous amount of time and effort to create Terminal 5. We remain confident that these early difficulties can be overcome, and that the terminal will be highly valued by customers and our staff in the near future and for many years to come."