Airports on the country’s east coast and serving the Balearics, including Barcelona’s El Prat, Palma, Ibiza and Menorca, may be affected after workers reportedly vowed to walk out unless their demands for changes to working hours were met.

Speaking to The Sun, a representative from an assembly representing the workers said some would even plan to leave their posts from the end of this week.

Raul Tobaruela revealed he was not optimistic an agreement would be reached as the group were currently being “ignored” by the Spanish government and Enaire, the air traffic service control provider in Spain and Western Sahara.

On Tuesday (June 19), Ryanair tweeted that due to staff shortages within UK, Greek, Portuguese and German ATC, delays had been caused to 74 flights, 17% of its 435 first wave of departures.

The low-cost carrier branded the disruption “unjustified”. There were delays on Monday morning (June 18) too due to the ongoing ATC strikes.

It comes after chief executive Michael O’Leary last week called for immediate “urgent action” to protect Europe’s ATC from “meltdown” following widespread staff shortages and strikes.

Meanwhile, all but one of the unions representing Air France workers have called off a four-day strike scheduled to begin this weekend.

Unions that called the action, planned over June 23-26, include those representing pilots, ground staff and air stewards 

Just one pilot union, the SPAF, has maintained its strike notice.

It is the latest twist in a long-running saga between Air France and its staff over pay, which also forced the airline’s boss, Jean-Marc Janaillac, to resign.