UK holidaymakers hoping to travel to Spain could soon find it more difficult. Ryanair says it is prepared to cut another one million seats to the destination if Aena, Spain's airport and air navigation authority, doesn't cancel its cost increases. Ryanair has already cut one million seats in Spain for the winter season, but there is a high possibility that number will double by next summer. 

The decision follows Aena's decision to increase airport charges by 6.62% next year, which Ryanair has criticised. The new charge is the highest that Spanish airports have seen in a decade.

Michael O'Leary, Ryanair's chief exectuive, told the Financial Times: "I am a due back in Madrid in two weeks, I will probably announce another one million seats coming out next summer.

"If the costs in regional Spain are too high, I will fly elsewhere. We are better off flying at the same cost to places such as Palma than flying to Jerez."

The budget airline, which carries more passengers to and from Spain than any other airline, has called on Aena to cancel the increases, with the chief exective stating that if Aena doesn't back down then he has "no desire to serve them anyway".

The carrier has announced that it will not be running any winter flights to certain Spanish airports, including Santiago de Compostela, Vigo, Valladolid, Jerez, and Tenerife. 

It has also claimed that Aena's new  €11.03 (£9.54) per passenger charge is "unjustified and harmful".

However, Aena hit back, accusing Ryanair of "extortion" and dishonesty, arguing that the airline had officially requested approval for more flights than it publicly claimed to be cancelling.

Spain is the second-largest market for Ryanair after Italy. However, despite the public dispute, the Ryanair boss claims that it has significant attention that has boosted the airline's bookings. 

He added: "Around half a million [seats] have already been redirected to Malaga and Palma, while others have gone to regional Italian destinations."

Ryanair is also pushing for Spain to reform the managment of Aena, which is 51% state-owned, and pressing the country to improve competitiveness of regional airports, which is says are "almost 70% empty due to a failed traffic structure".