LONDON – The union representing British Airways PLC pilots added its voice to criticism of the airline on Monday, claiming the carrier’s brand has become a “laughing stock” over woes at Heathrow’s new terminal and called for a change in management style.

The British Airline Pilots Association — or Balpa — said the recent debacle at Terminal 5 is symptomatic of problems that the union has been warning the airline about for years.

BA has canceled hundreds of flights and seen thousands of bags delayed at the terminal since it opened on March 27. Critics have blamed the mess on both BA and Heathrow’s operator BAA.

“It is with great sorrow and acute embarrassment that BA pilots have witnessed the unhappy, distressing shambles that the opening of T5 has become,” general secretary Jim McAuslan said in an open letter directed at both the government and London’s financial district.

“Banks, institutional investors and analysts need to wake up to the fact that there is something very wrong at the heart of this company that is making our once great brand a laughing stock,” he added.

The opening of Terminal 5 has been a public relations disaster for BA and BAA, which had hoped the new terminal would bring an end to frequent complaints about delays and overcrowding at the airport, Europe’s busiest.

BA said on Monday that it remained “absolutely committed to resolving the problems associated with the initial move into Terminal 5.”

More than a week after the terminal opened, BA is yet to run a full schedule of flights.

Heavy snow added to the airline’s woes on Sunday, causing the majority of a total of 185 flight cancellations into and out of the entire airport. BA said the knock-on effect of the weather disruption meant 35 short-haul flights to and from the new terminal would be canceled on Monday.

Balpa, which represents some 3,000 BA pilots, said the company’s reputation was now on the line, a fact that also affected the careers of its employees.

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

He said that 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,” he said.

The union stopped short of calling for Chief Executive Willie Walsh to be replaced.

The pilots’ criticism comes as it remains in dispute with BA over the carrier’s plans to start a new airline, OpenSkies, between mainland Europe and the United States which will recruit new pilots at anticipated lower pay and benefits. They fear that could flow through to their own positions.

Pilots had voted in favor of industrial action, but BA applied for a legal injunction to prevent a strike going ahead.