London's Heathrow tells airlines to stop ticket sales as it caps passengers

"We have therefore made the difficult decision to introduce a capacity cap with effect from 12 July to 11 September."

"We recognise that this will mean some summer journeys will either be moved to another day, another airport or be cancelled and we apologise to those whose travel plans are affected," he added.

The London hub said the cap was in line with limits implemented at its rivals. Schiphol in the Netherlands has capped passenger numbers about 16% lower than 2019 levels, while Frankfurt has cut flights at peak times from 104 per hour to 94.

Heathrow said the average number of outbound seats still remaining in the summer schedules was 104,000 a day, 4,000 above its cap. It said on average 1,500 of these 4,000 seats had been sold to passengers.

"We are asking our airline partners to stop selling summer tickets to limit the impact on passengers," Holland-Kaye said.

British Airways, Heathrow's biggest customer, has already cut 10,300 short-haul flights between August and October to minimise disruption after the British government offered amnesty if airlines did not use their slots.

Willie Walsh, director general of the International Air Transport Association (IATA) and a former CEO of British Airways, said Heathrow should have gotten its act together after airlines predicted a strong rebound in traffic.

"They clearly got it completely wrong," he told Reuters.

Heathrow on Monday apologised for the long queues and baggage issues customers had endured in recent weeks, blaming staff shortages across the whole aviation sector.