British Airways will pull an estimated 800 more flights from its summer schedule as the carrier looks to reduce last-minute cancellations amid continuing staffing shortages and long queues at airports.

The cuts—combined with the roughly 8,000 dropped flights announced in May—mean the unit of IAG SA has now reduced its timetable by 11% through October. The move follows the UK’s decision to waive rules requiring airlines to use takeoff and landing slots or lose them the next season.

“As the entire aviation industry continues to face into the most challenging period in its history, regrettably it has become necessary to make some further reductions,” a BA spokesman said Tuesday by email.  “We’re in touch with customers to apologize and offer to rebook them or issue a full refund.”

Airports and airlines across Europe are slashing capacity and canceling flights after being caught flatfooted by a surge of demand following two years of virtually no travel.