La sentencia se centra en analizar si resulta contrario al artículo 14 CE que una Administración Pública aplique una reducción de jornada a trabajadores temporales y fijos discontinuos, excluyendo a los fijos. Para ello, el Tribunal Constitucional aplica el canon habitual, basado en criterios básicos: 1) la existencia de dos situaciones comparables, 2) la concurrencia de un trato diferenciado a los trabajadores no fijos por el mero hecho de serlo y 3) sin que exista una causa objetiva que lo justifique.
De acuerdo con este esquema, siguiendo la última jurisprudencia del Tribunal Supremo, la sentencia agrupa a trabajadores temporales e indefinidos no fijos por no encontrar diferencias sustanciales entre ellos para, a continuación, declarar que la diferencia de tratamiento no se encuentra justificada desde un punto de vista objetivo pues, aunque se persiga un fin legítimo cual es el mantenimiento del empleo en la Administración, se hace recaer la carga que tales medidas exclusivamente sobre los trabajadores no fijos, lo que resulta desproporcionado.
The judgment analyses whether a Public Administration applies a reduction of working time to temporary workers and workers having contracts 'of indefinite duration but not permanent' ("indefinidos no fijos") whereas civil servants and permanent workers are excluded constitutes in a case of discrimination. Consequently, the Courts applies the principie of non-discrimination which requires: (1J two comparable situations; (2) in which fixed-term workers are not to be treated in a less favourable manner than comparable permanent workers solely beca use they have a fixed-term employment relationship, and (3) unless different treatment is justified on objective grounds: Regarding the first point, in the prívate sector, when a fixed-term employment contract is unlawful, in accordance with art. 15.3 and 5 of the Workers' Statute, that contract is deemed to be entered into for an indefinite duration. By contrast, in the public sector, in a similar situation, having regard to the constitutional principies of equality, merit and competence to which access to public employment is subject, these rules cannot be applied completely. This is the reason beca use the Spanish Court Created the so-called workers with contracts 'of indefinite duration but not permanent' ("indefinidos no fijos"), who enjoy the same rights of permanent workers except for the permanency. The Constitutional Court remembers this case law to conclude that workers having contracts 'of indefinite duration but not permanent' are in reality treated in the same manner as fixed-term workers and therefore differently to permanent workers.