LONDON (AP) — Mideast carrier Emirates on Thursday rejected a demand by London’s Heathrow Airport for airlines to cut summer flights in a bid to ease travel disruptions, calling it an “entirely unreasonable and unacceptable” move that shows “blatant disregard for customers.”

In a blistering statement, the airline lashed into Heathrow’s management, accusing it of “incompetence” for not being ready to deal with the “super peak period” for travel.

Emirates, one of the world’s biggest airlines, was firing back a day after Heathrow announced it was capping daily passenger numbers at 100,000 and telling airlines to stop selling tickets as it seeks to quell travel chaos caused by soaring travel demand and staff shortages.

Airlines have already slashed thousands of flights from their summer schedules after U.K. aviation authorities said they wouldn’t be punished for not using valuable takeoff and landing slots in a bid to prevent last-minute cancellations.

Heathrow, Britain’s busiest airport, said the cuts weren’t enough, but Emirates drew a line, exposing tensions between the airport and the airlines that are its customers.

Emirates, which operates six daily return flights between Heathrow and Dubai, United Arab Emirates, said it’s “highly regrettable” that the airport on Wednesday night gave it 36 hours to comply with capacity cuts “of a figure that appears to be plucked from thin air.”

“Their communications not only dictated the specific flights on which we should throw out paying passengers, but also threatened legal action for non-compliance,” the airline said.

Booming demand for summer travel after two years of COVID-19 travel restrictions have swamped airlines and airports in Europe, which are shorthanded after many pilots, cabin crew, check-in staff, and baggage handlers were laid off. That has left travelers facing last-minute cancellations, lengthy delays, lost luggage or long waits for bags.

Heathrow blames a shortage of ground staff, which are contracted by airlines to check-in passengers, load and unload bags, and prepare aircraft for their next journey.

Emirates, however, said its ground-handling and catering services are owned by its parent company and “are fully ready and capable of handling our flights.” Blame instead lies with the airport’s “central services and systems,” it said.

The airline accused Heathrow management of being “cavalier” about travelers and airlines, with signs of a strong travel rebound apparent for months.

Emirates said it got ready, including rehiring and training 1,000 pilots in the past year but that Heathrow failed to act, plan or invest.

“Now faced with an ‘airmageddon’ situation due to their incompetence and non-action, they are pushing the entire burden — of costs and the scramble to sort the mess — to airlines and travelers,” the statement said.

Heathrow said it has been asking airlines for months to help draw up a plan to solve their staffing challenges, “but no clear plans were forthcoming and with each passing day the problem got worse.”

“We had no choice but to take the difficult decision to impose a capacity cap designed to give passengers a better, more reliable journey and to keep everyone working at the airport safe,” Heathrow said in response to the Emirates statement. “It would be disappointing if instead of working together, any airline would want to put profit ahead a safe and reliable passenger journey.”

Rebooking so many potentially affected passengers is impossible because all flights for the next few weeks are full, including at other London airports and on other airlines, Emirates said. Moving some operations to other U.K. airports at short notice is also unrealistic, it said.