La STC 78/2010 anuncia una rectificación en la doctrina constitucional relativa a la cuestión prejudicial comunitaria, denegando el amparo constitucional instado por el Gobierno canario en un caso prácticamente idéntico a otro resuelto favorablemente en la STC 194/2006. Pero ¿cómo se fundamenta el cambio de criterio? En este comentario se indaga el verdadero sentido de tal cambio de doctrina, que en realidad sólo afecta a un supuesto concreto: el planteamiento de la cuestión prejudicial comunitaria por un juez estatal cuando la normativa comunitaria que entienda vulnerada no sea aplicable en un territorio de ese Estado. A tal efecto, se hace un detenido repaso por los pronunciamientos más relevantes en la materia, no sólo de nuestro Tribunal Constitucional, sino también del Tribunal de Justicia.
In its Judgment no. 78/2010 the Constitutional Court of Spain specifically announced a correction concerning its previous doctrine on the European preliminary ruling. In the instant case the Court rejected the request for constitutional protection filed by the Autonomous Government of the Canary Islands. However, in a virtually identical case in 2006, the Constitutional Court had ruled in favour of the plaintiff (Judgment no. 194/2006, of June 19). This study aims at discovering the real innovations behind the announcement of a new doctrine. For this purpose, the most significant judgments on the topic have been reviewed, not only the ones issued by the Constitutional Court but also those by the European Court of Justice. The author concludes that the aforementioned correction of the previous doctrine only takes place when it comes to a particular case: the request by a national Court for a preliminary ruling if the provision allegedly breached were not applicable in a particular territory.