easyJet (London Luton) has cancelled 1,700 flights in July, August, and September, mainly from London Gatwick, citing unprecedented air traffic control delays caused by Europe's congested skies exacerbated by Ukraine's air space closure due to Russia's war, staffing issues at air control stations, and industrial action.

The airline said making changes now would avert last-minute cancellations, which were more costly and caused passengers more inconvenience, Reuters reports.

The Independent newspaper reports that easyJet has rebooked 95% of 180,000 passengers affected by consolidating flights with multiple frequencies, but still leaving 9,000 passengers currently without a flight replacement.

An easyJet spokesman told MailOnline: "We are currently operating up to around 1,800 flights and carrying around 250,000 customers per day with more crew and pilots flying than ever before, and like all airlines, we review our flights on an ongoing basis.

The airline has maintained that disruptions are not due to staff shortages, which plagued the aviation sector last year.

"The whole industry is seeing challenging conditions this summer with more constrained air space due to the war in Ukraine resulting in unprecedented ATC delays, as well as further potential ATC [air traffic control] strike action. We have therefore made some pre-emptive adjustments to our programme, consolidating a small number of flights at Gatwick, where we have multiple daily frequencies, in order to help mitigate these external challenges on the day of travel for our customers and we continue to operate around over 90,000 flights over this period. Customers whose flights are affected are being informed, with 95% of customers being rebooked onto an alternative flight and all customers are provided with the option to rebook or receive a refund. We are sorry for any inconvenience that this may have caused."

A London Gatwick spokesman told The Telegraph: "Inbound flights at London Gatwick are increasingly being regulated at peak times due to the knock-on effects of air traffic control restrictions across numerous parts of Europe". He added: "These issues are beyond the control of the airport and have been put in place to manage and smooth out the flow of aircraft arriving from disrupted airspace across Europe. Multiple factors are causing airspace restrictions across Europe, including industrial action, staff shortages, the war in Ukraine and poor weather." The airport said it was working with airline partners to minimise disruption.

IATA Director General Willie Walsh, in a statement on July 12, said "the ATC environment that all carriers in Europe are experiencing is challenging". "The most severe impacts are being seen at Europe’s most congested airports, especially London Gatwick, where the performance is also affected by local ATC resource issues. Gatwick is now the worst-performing airport among the 31 major airports reported by Eurocontrol and sits at number 106 out of the 110 airports covered by the entire data set."

On July 7, Eurocontrol trade unions (Union Syndicale Bruxelles - USB) announced a six-month window during which industrial action could take place in the Eurocontrol Network Manager Operations Centre (NMOC) in Brussels. No specific dates for industrial action were announced. NMOC oversees air traffic across the European air traffic network, playing a pivotal role in managing, streamlining and improving air traffic operations.

In its latest traffic update on June 30, Eurocontrol said traffic to/from Spain was flourishing as holiday demand continued to rise. Nevertheless, as a gauge of the recovery, just three airlines, three airports and three states saw higher flight levels than in 2019. These were the Wizz Air Holdings (up 32%), Ryanair Holdings (up 25%) and Turkish Airlines (up 12%). The airports are Istanbul Airport (up 18%) and Antalya (up 7%) both in Türkiye; and Palma de Mallorca (up 1%) in Spain; while the countries are the three classic European summer destinations of Greece (up 10%), Türkiye (up 10%), and Portugal (up 8%).

ch-aviation has reached out to easyJet for comment.