It comes after Emirates said it would defy the airport’s orders to cut capacity on its flights, a move which the carrier described as "unreasonable and unacceptable". 

In a joint letter from the Department for Transport, director general for aviation, maritime and security and chief executive of the CAA, John Holland-Kaye has reportedly been given until noon on Friday (15 July) to assure them the airport is adequately staffed for security screening and to assist disabled passengers.

According to the letter, seen by The Telegraph, he has also been ordered to report back with a "credible and resilient" capacity recovery plan for the next six months.

Rannia Leontaridi from the DfT and CAA boss Richard Moriarty reportedly wrote: "Heathrow and the airlines that use your airport must be assured, and be able to assure us, that you have in place a plan that can deliver a positive passenger experience through allowing as many people as possible to travel, without too much disruption and queues, and in particular to avoid significant numbers of short-notice and on-the-day cancellations.

"The government and the CAA are concerned that current resourcing plans are not delivering this outcome."