1) This request for a preliminary ruling concerns the interpretation of Clause 4(1) of the framework agreement on fixed-term work concluded on 18 March 1999 (‘the Framework Agreement’), which is annexed to Council Directive 1999/70/EC of 28 June 1999 concerning the framework agreement on fixed-term work concluded by ETUC, UNICE and CEEP (OJ 1999 L 175, p. 43), and the interpretation of Article 21 of the Charter of Fundamental Rights of the European Union (‘the Charter’).

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28) If the different treatment cannot be considered justified by social-policy objectives, the referring court states that it would be impossible to adopt an interpretation of Article 49(1)(c) of the Workers’ Statute that is compatible with the Framework Agreement. In those circumstances, the referring court is uncertain whether, in the light of the Court’s case-law resulting from the judgments of 22 November 2005, Mangold (C‑144/04, EU:C:2005:709), of 19 January 2010, Kücükdeveci (C‑555/07, EU:C:2010:21), of 13 September 2011, Prigge and Others (C‑447/09, EU:C:2011:573), and of 19 April 2016, DI (C‑441/14, EU:C:2016:278), the prohibition on different treatment between fixed-term workers and permanent workers also stems from the principle of equal treatment and non-discrimination enshrined in Articles 20 and 21 of the Charter.

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29) It is in those circumstances that the Tribunal Superior de Justicia de Galicia (High Court of Justice, Galicia) decided to stay proceedings and to refer to the Court the following questions for a preliminary ruling:

‘(1) For the purposes of the principle of equal treatment between temporary and permanent workers, must the termination of an employment contract due to “objective circumstances” under Article 49(1)(c) of the Workers’ Statute and the termination of an employment contract on “objective grounds” under Article 52 of the Workers’ Statute be regarded as “comparable situations” and, accordingly, does the difference between the compensation payable in each case constitute unequal treatment between workers with fixed-term contracts and those with contracts of indefinite duration, prohibited by Directive [1999/70]?

(2) If so, must the social-policy objectives that justified the creation of the “contrato de relevo” model of contract also be deemed to justify, under Clause 4(1) of [the Framework Agreement], the difference in treatment consisting in the payment of a lower amount of compensation for termination of the employment relationship when the employer freely decides that such a “contrato de relevo” should be for a fixed term?

(3) For the purposes of guaranteeing the practical effect of Directive 1999/70/EC, if there should be found to be no reasonable justification under Clause 4(1), is the unequal treatment of temporary and permanent employees with regard to compensation for termination of their contracts, as provided for in the Spanish legislation referred to above, to be interpreted as constituting discrimination of the kind prohibited by Article 21 of the [Charter] and, therefore, as contrary to the principles of equal treatment and non-discrimination that are part of the general principles of EU law?’