The British Airline Pilots Association (Balpa), which represents 3,000 BA pilots, said it could no longer stay silent because of the T5 "debacle".

General secretary Jim McAuslan said the company's reputation was now on the line adding that this also affected the careers of its staff.

In an open letter aimed at city institutions as well as the Government, Mr McAuslan accused BA of taking its eye off the ball and said it was time it was held to account.

"Failings on the opening days of T5 are symptomatic of BA's loss of focus in delivering a sound operation.

"The airline can and should make Britain proud but a fundamental change of attitude is required from the very highest levels of BA management."

Mr McAuslan said Balpa had been pressing BA for years to focus on punctuality, baggage delivery and product quality.

"Get that right and the customers will keep coming back in today's highly competitive aviation market.

"It is with great sorrow and acute embarrassment that BA pilots have witnessed the unhappy, distressing shambles that the opening of T5 has become.

"BA pilots have reacted in the right way by once again going the extra mile to solve problems and extend their working duties to maximum legal limits in order to minimise the suffering of our customers and protect the company they love and the uniform they wear."