British Airways expects to cancel hundreds more flights at its global hub at London Heathrow airport this week, as it battles to overcome baggage handling and other operating problems at its showpiece £4.3bn Terminal 5.

The airline is struggling to deal with a mountain of more than 15,000 misplaced bags, which has been growing since last Thursday’s long-awaited opening of T5, which was supposed to open a new era of improved passenger service at Heathrow.