IAG chief Willie Walsh and Ryanair boss Michael O’Leary hit out at Europe’s air traffic control this week, denouncing a wave of strikes and staff shortages.

Walsh, chief executive of International Airlines Group – parent of British Airways, Iberia, Aer Lingus, Vueling and Barcelona-based LEVEL – described the air traffic control (ATC) strikes in Europe as “the greatest challenge to the industry”.

He told the conference of the UK’s Guild of Travel Management Companies (GTMC) in Ireland: “Airlines cancelled about 1,000 flights in May and will probably cancel more in June.

“This is the greatest challenge to the industry this year and next. Something has to happen.”

Walsh said: “The strikes in the Marseilles area disrupt most of the Mediterranean.” Yet he argued: ““It is estimated only about 20 people in Marseilles are leading these strikes.”

He insisted: “Michael O’Leary and I will be addressing this in Brussels next week. We need to make the politicians understand.”

In a separate statement, O’Leary said: “Yet again this weekend, French ATC will strike on Saturday and Sunday leading to hundreds of flights being cancelled.

“Many of these flights don’t even touch France, yet they will be disrupted because French ATC requires airlines to cancel overflights while they protect French domestic routes.”

O’Leary also hit out at staff shortages, accusing ATC providers of blaming the weather “to cover shortages” and demanded European governments take urgent action “to prevent a meltdown”.

Ryanair claimed more than 71,000 flights were delayed due to ATC staff shortages and strikes in May, out of a total of 117,000 delays – although only about half this total (56,000) were delayed by more than 15 minutes.

The carrier said weather delays accounted for 39% of the total and argued: “Almost 60% of these weather delays took place on Fridays and Saturdays, which suggests ATC providers are using adverse weather to cover staff shortages.”

Ryanair reported it cancelled “just over 1,000 flights” in May, almost all due to ATC staff shortages and strikes, and EasyJet cancelled 974 flights.

O’Leary warned: “Thousands more flights and millions of passengers will be disrupted in the peak months of July and August.

He said: “The situation is acute at weekends where British and German ATC providers are hiding behind adverse weather and euphemisms such as ‘capacity restrictions’ when they are not rostering enough staff to cater for the number of flights scheduled to operate.

“We call on the UK and German governments and the EC to take urgent and decisive action to ensure ATC providers are fully staffed and that overflights are not affected when strikes take place.”