Dozens of flights have been cancelled from Heathrow Airport this morning, with more expected to come this summer.
More than 10,000 passengers are expected to be impacted by the last minute groundings at Britain's biggest airport.
Before lunchtime today 60 flights will be cancelled, made up of 48 outbound and 15 arrivals.
The airline most affected is British Airways, which has had a torrid week, announcing further massive schedule cuts last week which reduced its total summer roster to 18% of usual.
Have you had your flights or holiday cancelled this summer? Email webtravel@reachplc.com
British Airways departures that have been cancelled so far include services to Dublin, Edinburgh, Glasgow and Aberdeen, although some of these are planned cancellations.
BA long-haul departures to New York JFK and Austin are also understood to have been grounded.
Air France has grounded services to Paris, while Virgin Atlantic has cancelled planes to Austin and Delhi.
A Heathrow spokesperson apologised for the latest spate of travel misery that has come from an airport struggling to deal with demand this summer.
“We are expecting higher passenger numbers in Terminals 3 and 5 tomorrow than the airport currently has capacity to serve, and so to maintain a safe operation we have asked some airlines in Terminals 3 and 5 to remove a combined total of 48 flights from the schedule," they said on Sunday evening.
“We apologise for the impact to travel plans and we are working closely with airlines to get affected passengers rebooked onto other flights.”
Because the cancellations have been called for by the airport and not the airline, it is judged to be beyond the airline's control.
As such impacted customers are not entitled to compensation.
Figures from Heathrow Airport show that while passenger numbers have bounced back somewhat following the coronavirus lockdowns, they're not back up to 2019 levels.
Between January and June 2022, the airport handled 26 million passengers – two-thirds of the 39 million who passed through Heathrow in the same six months in 2019.
The airport's CEO John Holland-Kaye said: "I am very proud of the way that our team is rising to the challenge of growth, and giving excellent service to the vast majority of passengers.
"However, we have already seen times recently when demand exceeds the capacity of the airport, airlines and ground handlers.
"We will review the schedule changes that airlines have submitted in response to the government's requirement to minimise disruption for passengers this summer and will ask them to take further action if necessary."