Consumer group Which? says airlines must be prepared to give up valuable slots at Heathrow to their rivals if queues are to be avolded this summer at the terminals

  Heathrow and British Airways have both welcomed slot reductions with a chance to re-draw timetables and reduce cancellations

 But in a statement Rory Boland of Which warned the measure would only work if airlines ended the wasteful practise of flying near-empty planse to preserve their slots.