A spokesman for the Civil Aviation Authority said last night that the Spanish ruling would have to be upheld in the European courts before it could be enforced at British airports.
Simon Evans, chief executive of the Air Transport Users Council added that most passengers using Ryanair in Britain were aware of the charge and printed their passes at home.
"The charges are part of the airline's strategy of stripping out costs."
A Ryanair spokesman, who said the airline would appeal, played down the significance of the ruling.
“Over 99.9% of Ryanair’s passengers used our web check in facility last year," he said.
"Seventy three million passengers this year can’t be wrong: checking in online from the comfort of your home and avoiding airport queues is clearly what passengers want, and Ryanair will defend their interest by appealing this decision.
"It is remarkable that a Spanish judge could possibly suggest that this agreement between Ryanair and its passengers was breaking international law.”
Source: The Telegraph