Emirates has rejected an order from Heathrow to cancel flights to comply with a cap on passenger numbers.
The airline accused the west London airport of showing “blatant disregard for consumers” by attempting to force it to “deny seats to tens of thousands of travellers” through the cap.
A Heathrow spokeswoman said it would be “disappointing” if “any airline would want to put profit ahead a safe and reliable passenger journey”.
Virgin Atlantic also criticised the airport’s actions and claimed it was responsible for failures which are contributing to the chaos.
British Airways announced it will cancel six additional daily short-haul flights over the next fortnight in response to the cap.
Emirates plans to operate as scheduled
It has already axed tens of thousands of flights this summer.
On Tuesday, Heathrow introduced a cap of 100,000 daily departing passengers until September 11, and pleaded with carriers to stop selling summer tickets.
Many passengers flying to and from the UK’s busiest airport have suffered severe disruption in recent months, with long security queues and baggage system breakdowns.
Emirates, which operates six daily return flights between the airport and Dubai, said in a statement: “LHR (London Heathrow) last evening gave us 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.
“This is entirely unreasonable and unacceptable, and we reject these demands.
“Until further notice, Emirates plans to operate as scheduled to and from LHR.”
The Gulf carrier said its ground handlers at Heathrow are “fully ready and capable of handling our flights”, which means “the crux of the issue lies with the central services and systems which are the responsibility of the airport operator”.
It stated it would be “impossible” to re-book the number of passengers that would be affected by Heathrow’s cancellation demands.
The Heathrow spokeswoman said aviation is “a complex network” and “no-one can operate in isolation”.
She explained that staffing for ground handling teams at the airport are only at 70% of pre-pandemic levels, whereas passenger numbers are at 80-85%.
She went on: “For months we have asked airlines to help come up with a plan to solve their resourcing 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.”
She noted the cap is “significantly higher” than the 64,000 imposed at Amsterdam’s Schiphol airport.
“It would be disappointing if instead of working together, any airline would want to put profit ahead a safe and reliable passenger journey,” she added.
In December last year, Heathrow said it expected passenger numbers for 2022 to reach around 45 million.
It subsequently raised its forecast to “nearly 53 million” in May, and 54.4 million in June.
Terminal 4 was only reopened on June 14, some three months after the UK lifted all remaining coronavirus travel restrictions.
It was the last terminal at a major European airport to resume operations during the pandemic.
Virgin Atlantic chief customer and operating officer Corneel Koster said “everybody should have got ready for this increased demand”.
He told the PA news agency: “If you’re around the table and the Heathrow voice says ‘it won’t happen, it will come later, I will only open my fourth terminal in June’, that’s a planning mistake.
“They have downplayed demand. They should have opened T4 earlier.
“They should have played an even stronger role in the community.”
A British Airways spokesman said the cap is “incredibly disappointing” as it has already taken “responsible action to reduce our summer schedule”.
The Department for Transport’s director general for aviation Dr Rannia Leontaridi and Civil Aviation Authority chief executive Richard Moriarty wrote a joint letter to Heathrow boss John Holland-Kaye requesting his assessment of why the airport determined that a cap of 100,000 daily departing passengers “provides a safe and resilient airport with a positive passenger experience”.
The letter, seen by PA, continued: “We need you to develop a credible and resilient capacity recovery plan for the next six months, that provides comfort that Heathrow can operate reliably at a stable level of capacity.”