Ryanair is to seek a refund of €15 million in taxes and fines after the European Court of Justice upheld EU rules on social insurance payments for international transport workers.

The airline said the ruling confirmed that French social insurance authorities acted unlawfully over ten years by double charging Ryanair and staff who were based temporarily in Marseille, but who had already fully paid their social insurance in Ireland in accordance with EU regulations.

Ryanair will now pursue a full refund of €10 million plus interest it has paid in double taxes to the French state between 2006 and 2010.

French authorities had tried to pursue Ryanair for social insurance payments for its pilots and cabin crews who were operating on temporary summer schedules from Marseille between 2011 and 2014.

A similar ‘double tax’ situation also exists in Italy where there are several outstanding claims from 2006 to 2011 being pursued by Italian authorities for payment of social insurance when these contributions have already been paid by Ryanair pilots and cabin crew in Ireland.

Lawyers for the airline will be writing to the Italian authorities to withdraw these claims “as they now have no prospect of success” given the clear ruling of the European court.

Ryanair chief people officer, Eddie Wilson, said: “We welcome this ruling which upholds the existing EU rules on social insurance payments for international transport workers, and exposes the unlawful attempt by the French – and to a lesser extent the Italian – authorities, to threaten Ryanair for the double payment of social insurance in the case of pilots and cabin crew who have already paid their social insurance contributions in Ireland, in full compliance with EU rules.

“Ryanair will now be pursuing a full refund of €15 million plus interest from the French authorities who have repeatedly and unlawfully pursued Ryanair, its pilots and cabin crew in Marseille, by ignoring EU regulations, and the validly issued Irish A1 certificates.

“We will also be pursuing the French authorities for interest on these payments.

“We expect the French authorities will now process these refunds expeditiously given that their attempts to force Ryanair to double pay social insurance in breach of EU rules have now been struck down by this very welcome ECJ ruling.”