Ryanair cabin crew in four countries, including Spain, announced in Brussels on Thursday that they will go on strike on 25 and 26 July.
The action comes after unions failed to obtain a commitment from the airline to apply the conditions established in the labour laws in the countries in which the employees are based - Spain, Portugal, Italy and Belgium - rather than the Irish legislation.
Ryanair has responded, saying their demands "don't make sense", bearing in mind their current conditions.
The stoppages will be carried out in all four countries, announced the unions Sitcpla and USO (Spain); SNVPAC (Portugal); UIL (Italy) and CNE (Belgium).
The USO explained that more than 1,800 Ryanair cabin crew have been called to strike in Spain, with the figures reaching 4,000 in all four countries. The airline currently operates around 2,000 flights a day from 89 hubs in Europe, 13 of them in Spain, including Malaga.
Sitcpla stated that some 120,000 passengers could be affected on each day of the strike in Spain.
"Ryanair must apply the national legislation to the crew's contracts," said a Sitcpla representative on Thursday, adding that the airline should "incorporate the European values of dignity and respect".
The president of Sitcpla, Monique Duthiers, said that those speaking in Brussels on Thursday were representatives as the employees themselves did not want to speak out in public.
"In 2018 in the EU there is still fear of reprisals from an employer in the event of a strike," said Duthiers, who asked the press not to take photographs of the Ryanair staff present in the room to protect them.
"What no one understands is how they have managed to get so far. We are talking about an Irish company in the European Union in the 21st century that has failed to comply with European and national regulations," added Duthiers.
In the name of the employees, the unions reported practices such as calling workers to airports to cover flights that in the end didn't take off and refusing to pay them for the hours spent waiting, as well as applying Irish or local legislation for maternity and paternity leave, depending on which was more beneficial for the company.
The USO has said that the mediation and arbitration service SIMA, has called the Spanish unions and Ryanair to a conciliation session on 10 July to negotiate the conflict. If the company does not attend or no agreement is reached the strike will go ahead as announced.
"The number of flights affected will depend on the minimum essential service regulations in each country: Allthough, based on the participation in the first and only strike called until now by Ryanair cabin crew in Portugal, delays and cancellations of dozens of flights in the four countries are expected," said Ernesto Iglesias, head of the Flight section at the USO Air Sector.
In response to the strike announcement on Thursday, Ryanair defended the conditions currently enjoyed by its cabin crew, who could earn up to 40,000 euros a year, "more than twice the minimum wage".
The employers also pointed out that they work for five consecutive days and then have three days off, which means they have a "long weekend" every week, conditions that exceed the minimum requirements of the EASA (European Aviation Safety Agency).
The airline went on to list more conditions that currently apply to the cabin crew, such as sick pay, a 10% bonus for selling products in the cabin and an annual allowance of 400 euros for uniforms.
The cabin crew action comes after the Irish Airline Pilots Association (IALPA) called Ryanair pilots based in Ireland to strike on Thursday 12 July. The head of Human Resources at the airline, Eddie Wilson, has called the pilots to a meeting on 11 July to negotiate and call off the strike.