UK airlines have been told to cancel flights they can't deliver this summer to stop a rerun of May's travel chaos.
The government and the aviation regulator wrote to carriers on Tuesday telling them to ensure their summer timetables were "deliverable".
They added that earlier cancellations were "better" than axing flights at the last minute.
It comes after tens of thousands of passengers have been affected by cancellations and delays at airports.
The problem was particularly bad during Easter and last month's half-term school holiday, and British Airways, TUI and Easyjet have apologised.
Staff shortages have been blamed, after thousands of airline jobs were cut during the pandemic and have yet to be replaced despite a spike in post-pandemic travel demand.