OPINION OF ADVOCATE GENERAL
RANTOS
delivered on 25 January 2024 (1)
Case C‑743/22
DISA SUMINISTROS Y TRADING, S.L.U. (DISA)
v
Agencia Estatal de la Administración Tributaria
(Request for a preliminary ruling from the Tribunal Supremo (Supreme Court, Spain))
(Reference for a preliminary ruling – Taxation of energy products and electricity – Directive 2003/96/EC – Article 5 – Excise duty on mineral oils – Regional rate of excise duties on mineral oils on top of the national rate – Differentiated rates of excise duties in the territory of a Member State according to the region in which the product is consumed)
I. Introduction
1. This request for a preliminary ruling concerns the interpretation of Article 5 of Directive 2003/96/EC. (2)
2. The request has been made in proceedings between DISA Suministros y Trading, S.L.U. (‘DISA’ or ‘the appellant’) and the Agencia Estatal de la Administración Tributaria (State Tax Administration Agency, Spain) further to claims by the appellant for the reimbursement of taxes paid in respect of the additional rate of taxation applied by an autonomous community on the excise duty on mineral oils (impuesto especial sobre hidrocarburos; ‘the IEH’).
3. This case gives the Court the opportunity to clarify whether, irrespective of compliance with the minimum levels of taxation required by Directive 2003/96, that directive requires that a uniform level of taxation applies throughout the territory of a Member State, or whether the directive affords the Member States some leeway to provide for different rates of excise duty for the same product and the same use, depending on the part of the national territory in which that product is intended to be consumed.
II. Legal context
A. European Union law
1. Directive 2003/96
4. Recitals 2 to 5, 9, 10, 15 and 24 of Directive 2003/96 state:
‘(2) The absence of Community provisions imposing a minimum rate of taxation on electricity and energy products other than mineral oils may adversely affect the proper functioning of the internal market.
(3) The proper functioning of the internal market and the achievement of the objectives of other Community policies require minimum levels of taxation to be laid down at Community level for most energy products, including electricity, natural gas and coal.
(4) Appreciable differences in the national levels of energy taxation applied by Member States could prove detrimental to the proper functioning of the internal market.
(5) The establishment of appropriate Community minimum levels of taxation may enable existing differences in the national levels of taxation to be reduced.
…
(9) Member States should be given the flexibility necessary to define and implement policies appropriate to their national circumstances.
(10) Member States wish to introduce or retain different types of taxation on energy products and electricity. To that end, Member States should be permitted to comply with the Community minimum taxation levels by taking into account the total charge levied in respect of all indirect taxes which they have chosen to apply (excluding VAT).
…
(15) The possibility of applying differentiated national rates of taxation to the same product should be allowed in certain circumstances or permanent conditions, provided that Community minimum levels of taxation and internal market and competition rules are respected.
…
(24) Member States should be permitted to apply certain other exemptions or reduced levels of taxation, where that will not be detrimental to the proper functioning of the internal market and will not result in distortions of competition.’
5. Article 1 of that directive provides:
‘Member States shall impose taxation on energy products and electricity in accordance with this Directive.’
6. Article 2(1)(b) of the directive reads as follows:
‘1. For the purposes of this Directive, the term “energy products” shall apply to products:
…
(b) falling within CN codes 2701, 2702 and 2704 to 2715’.
7. Article 3 of that directive provides:
‘References in Directive 92/12/EEC to “mineral oils” and “excise duty”, in so far as it applies to mineral oils, shall be interpreted as covering all energy products, electricity and national indirect taxes referred to respectively in Articles 2 and 4(2) of this Directive.’
8. Article 4 of Directive 2003/96 provides:
‘1. The levels of taxation which Member States shall apply to the energy products and electricity listed in Article 2 may not be less than the minimum levels of taxation prescribed by this Directive.
2. For the purpose of this Directive “level of taxation” is the total charge levied in respect of all indirect taxes (except VAT) calculated directly or indirectly on the quantity of energy products and electricity at the time of release for consumption.’
9. Article 5 of that directive states:
‘Provided that they respect the minimum levels of taxation prescribed by this Directive and that they are compatible with Community law, differentiated rates of taxation may be applied by Member States, under fiscal control, in the following cases:
– when the differentiated rates are directly linked to product quality;
– when the differentiated rates depend on quantitative consumption levels for electricity and energy products used for heating purposes;
– for the following uses: local public passenger transport (including taxis), waste collection, armed forces and public administration, disabled people, ambulances;
– between business and non-business use, for energy products and electricity referred to in Articles 9 and 10.’
10. Article 6 of the directive provides:
‘Member States shall be free to give effect to the exemptions or reductions in the level of taxation prescribed by this Directive either:
(a) directly;
(b) by means of a differentiated rate,
or
(c) by refunding all or part of the amount of taxation.’
11. Article 19(1) and (3) of that directive provides:
‘1. In addition to the provisions set out in the previous Articles, in particular in Articles 5, 15 and 17, the Council, acting unanimously on a proposal from the Commission, may authorise any Member State to introduce further exemptions or reductions for specific policy considerations.
A Member State wishing to introduce such a measure shall inform the Commission accordingly and shall also provide the Commission with all relevant and necessary information.
The Commission shall examine the request, taking into account, inter alia, the proper functioning of the internal market, the need to ensure fair competition and Community health, environment, energy and transport policies.
…
3. If the Commission considers that the exemptions or reductions provided for in paragraph 1 are no longer sustainable, particularly in terms of fair competition or distortion of the operation of the internal market, or in terms of Community policy in the areas of health, protection of the environment, energy and transport, it shall submit appropriate proposals to the Council. The Council shall take a unanimous decision on these proposals.’
2. Directive 2008/118/EC
12. Article 1(1) and (2) of Directive 2008/118/EC (3) reads as follows:
‘1. This Directive lays down general arrangements in relation to excise duty which is levied directly or indirectly on the consumption of the following goods (hereinafter “excise goods”):
(a) energy products and electricity covered by [Directive 2003/96];
…
2. Member States may levy other indirect taxes on excise goods for specific purposes, provided that those taxes comply with the Community tax rules applicable for excise duty or value added tax as far as determination of the tax base, calculation of the tax, chargeability and monitoring of the tax are concerned, but not including the provisions on exemptions.’
B. Spanish law
13. Article 50ter of Ley 38/1992 de Impuestos Especiales (Law 38/1992 on excise duties), of 28 December 1992 (‘the Law on excise duties’), entitled ‘Autonomous community rate of taxation’, provides, in the version applicable to the dispute in the main proceedings:
‘1. The autonomous communities may establish a regional rate of excise duty on mineral oils, in order to levy additional tax on the goods to which the rates of taxation referred to in paragraphs … apply, and which are consumed in their respective territories. The regional rate shall be applied in accordance with this Law and within the limits and subject to the conditions laid down in the rules governing the financing of the autonomous communities.
2. The applicable regional rate of taxation shall be that corresponding to the autonomous community in whose territory the final consumption of the taxable goods takes place. For the purposes of this article, goods shall be understood to be consumed in the territory of an autonomous community where they are received in one of the following locations:
…’
14. Article 50ter of the Law on excise duties was in force during the 2013 to 2018 financial years. It was repealed with effect from 1 January 2019 by Ley 6/2018 de Presupuestos Generales del Estado para 2018 (Law 6/2018 on the general State budget for 2018) of 3 July 2018, the explanatory memorandum to which states inter alia:
‘In relation to excise duties, the regional rate of the duty on mineral oils is included in the special State rate in order to ensure a unified market in the field of fuels and propellants, without that measure adversely affecting the resources of the autonomous communities and within the Community legal framework.’
III. The dispute in the main proceedings, the question referred for a preliminary ruling and the procedure before the Court
15. The entities CLH, TEPSA and SECICAR, which are logistics operators subject to the IEH, filed self-assessments for the periods from 2013 to 2015 inclusive and passed on the amount of the IEH to DISA. The latter operates in the field of the purchase, sale, importation and wholesale marketing of petroleum products.
16. After paying the IEH, DISA applied to the tax authority seeking the correction of the self-assessments filed by CLH, TEPSA and SECICAR and claimed the reimbursement of the amounts corresponding to the additional regional rate of excise duties on mineral oils, as set by the autonomous community concerned (‘the regional rate of excise duties on mineral oils’ or ‘the regional rate of the IEH’).
17. In support of its claims, DISA argued that that regional rate, provided for in Article 50ter of the Law on excise duties, in force since 1 January 2013, was contrary to EU law in that it infringed certain provisions of Directive 2003/96, and in particular Article 5 thereof, because it does not correspond to the derogations laid down in that provision with a view to applying differentiated rates of taxation and that it was contrary to the objective of unified taxation under that directive.
18. The tax authority rejected those claims, considering that it was not for it to rule on whether or not the Spanish legislation infringed EU law.
19. The applicant then challenged that rejection before the Tribunal Económico-Administrativo Central (Central Tax Tribunal, Spain).
20. The applicant subsequently brought an appeal against the rejection of its claims before the chamber dealing with administrative litigation of the Audiencia Nacional (National High Court, Spain), which was dismissed by judgment of 25 November 2020. Whilst observing that the legal doubts raised by the interpretation of Directive 2003/96 could lead to it making a request for a preliminary ruling, the Audiencia Nacional (National High Court) rejected the claim for reimbursement of the amounts paid because DISA had not shown that it had not passed on those amounts to other persons, which could have given rise to its unjust enrichment.
21. The appellant lodged an appeal in cassation against the judgment of the Audiencia Nacional (National High Court) before the Tribunal Supremo (Supreme Court, Spain), the referring court.
22. That court notes that the outcome of the dispute in the main proceedings turns on the interpretation of Directive 2003/96, having regard to the regional rate of excise duties on mineral oils. It takes the view, in that regard, that neither that directive nor the case-law of the Court provides a clear interpretation of Article 5 of that directive as to whether, and in which circumstances, it precludes differentiated rates of taxation to the same product, according to the territory concerned, from being introduced within a Member State in respect of the taxation of energy products and electricity.
23. In those circumstances, the Tribunal Supremo (Supreme Court) decided to stay the proceedings and to refer the following question to the Court of Justice for a preliminary ruling:
‘Must Directive [2003/96], in particular Article 5 thereof, be interpreted as precluding a national provision, such as Article 50ter of [the Law on excise duties], which authorised the autonomous communities to set differentiated rates of the exercise duties on mineral oils for each territory in respect of the same product?’
24. Written observations were submitted to the Court by the appellant, the Spanish Government and the European Commission.
IV. Analysis
A. Admissibility of the question referred for a preliminary ruling
25. Before analysing the only question referred for a preliminary ruling by the referring court, it is necessary to rule on the plea of inadmissibility raised by the Spanish Government.
26. That government claims that the question referred for a preliminary ruling should be declared inadmissible because it is hypothetical. In its view, the question of the compatibility of the national provision at issue with EU law was never discussed either before the lower courts seised of the dispute in the main proceedings or in the context of the appeal before the referring court, since that appeal was initially limited to the question of the appellant’s standing to bring proceedings for the recovery of undue payments.
27. In that regard, it should be borne in mind that it is settled case-law that questions on the interpretation of EU law referred by a national court in the factual and legislative context which that national court is responsible for defining, the accuracy of which is not a matter for the Court to determine, enjoy a presumption of relevance. The Court may refuse to rule on a question referred for a preliminary ruling by a national court only where it is quite obvious that the interpretation of EU law that is sought bears no relation to the actual facts of the main action or its object, where the problem is hypothetical, or where the Court does not have before it the factual or legal material necessary to give a useful answer to the questions submitted to it. (4)
28. However, in the present case, the question submitted by the referring court is directly related to the actual facts of the main action or its object, in so far as that action concerns a claim made by the applicant for reimbursement of the amount corresponding to the regional tranche of the IEH which it paid, on the ground that that regional tranche is contrary to Directive 2003/96, in particular Article 5 thereof. The referring court observes, moreover, that the outcome of the dispute in the main proceedings turns on the interpretation of that directive since it will be required to rule on the substance of the complaint in accordance with the national law governing appeals in cassation. (5) Lastly, it is clear from the order for reference, and not contested by the Spanish Government, that the claims for reimbursement made by the applicant relate to a period during which Article 50ter of the Law on excise duties was in force.
29. In the light of the foregoing, the plea of inadmissibility raised by the Spanish Government must be dismissed.
B. Substance
30. By its sole question referred for a preliminary ruling, the referring court asks, in essence, whether Directive 2003/96, in particular Article 5 thereof, precludes a national rule, such as Article 50ter of the Law on excise duties, which authorises the autonomous communities to set differentiated rates of the excise duties on mineral oils for each territory, even though the minimum rates of taxation required by that directive are met.
1. Preliminary observations
31. As a preliminary point, it must be observed that the present case is characterised by the fact that the national provision at issue allowed each autonomous community in Spain to set its own regional rate of excise duty on mineral oils on top of the national rate of excise duty. (6)
32. Furthermore, as is apparent from the description of the national legal framework set out in point 14 of this Opinion, the Spanish Government amended Article 50ter of the Law on excise duties, which was in force in Spain over the 2013 to 2018 financial years, by repealing the additional regional rate with effect from 1 January 2019. (7) Since its repeal, the Kingdom of Spain has introduced an alternative system of financing the autonomous communities, which provides for a uniform rate throughout its territory. (8)
2. The main components of the harmonised system of taxation provided for in Directive 2003/96
33. It must be observed that, by providing for a harmonised system of taxation of energy products and electricity, Directive 2003/96 seeks, as is clear from recitals 2 to 5 and 24 thereof, to promote the proper functioning of the internal market in the energy sector, in particular by avoiding distortions of competition. (9) That directive thus intends to reduce the differences between national levels of energy taxation, since it has been found that that was a factor detrimental to the proper functioning of the internal market. (10)
34. In order to achieve that objective, the EU legislature proceeded not with an exhaustive but with a partial harmonisation of the rules on the taxation of energy products and electricity, since Directive 2003/96 merely sets harmonised minimum levels of taxation. (11) To that end, pursuant to Article 4(1) of that directive, the directive requires that the levels of taxation which Member States apply to the energy products and electricity listed in Article 2 thereof must not be lower than the minimum levels prescribed therein.
35. However, recognising both the need to give Member States the flexibility necessary to define and implement policies appropriate to their national circumstances and the fact that the arrangements introduced in connection with the implementation of Directive 2003/96 are a matter for each Member State to decide, that directive afforded the Member States some leeway and discretion in relation to excise duties. (12) That directive thus contains a series of provisions (including, in particular, Articles 5, 7 and 15 to 19) which provide for the possibility for Member States to introduce, subject to certain conditions, differentiated rates of taxation, exemptions from taxation or reductions in excise duties. (13)
3. The compatibility of the IEH with Article 5 of Directive 2003/96
36. With regard to Article 5 of Directive 2003/96, it must be observed that that provision lists the situations in which Member States may apply differentiated rates of taxation to the same product.
37. However, it must be stated, from the outset, that the application of differentiated rates between different regions within the same Member State is not, a priori, one of the situations provided for in that article. None of the cases listed in Article 5 of that directive provides for the possibility of applying a regional differentiation in excise duties. Moreover, the use of the expression ‘in the following cases’ to designate the situations in which a differentiation in the level of taxation would be possible under that provision appears to leave no room for doubt that the list of cases in which Member States may apply differentiated rates of taxation to the same product is exhaustive. (14) That interpretation is also apparent, moreover, from recital 15 of that directive, which provides that ‘the possibility of applying differentiated national rates of taxation to the same product should be allowed in certain circumstances or permanent conditions, provided that Community minimum levels of taxation and internal market and competition rules are respected’. (15)
38. In that connection, the case-law of the Court likewise seems to have confirmed that the list of situations set out in Article 5 of Directive 2003/96 is exhaustive, clarifying that that article provides for differentiated rates of taxation in certain cases ‘exhaustively listed in that article’. (16)
39. However, as the referring court rightly observes, it must be noted that the current case-law of the Court on Directive 2003/96, and in particular of Article 5 thereof, has not expressly examined the question of the uniformity of the excise duties for the same product and the same use within a Member State.
40. While, in the context of two actions for failure to fulfil obligations in which regionally differentiated rates of excise duty similar to those in the dispute in the main proceedings were regarded as disputed by the Commission in the light of Directive 2003/96, (17) and the question of whether or not that directive authorised such a regional differentiation was debated between the parties, the Court did not explicitly rule on that issue in the corresponding judgments. Thus, in the judgment in Commission v France, the Court simply found that the French Republic had failed to fulfil its obligations because it had not adapted its system of taxation of electricity to Directive 2003/96 within the prescribed period. This was also the case in the judgment in Commission v Italy (Contribution towards the purchase of motor fuel), in which the Court, given that the failure to fulfil obligations alleged by the Commission had not be demonstrated by that institution, was not required to rule on that question. (18)
41. The question referred for a preliminary ruling in the present case is open to two possible interpretations: the first interpretation, put forward by the Spanish Government, to the effect that Article 5 of Directive 2003/96 does not preclude the existence of differentiated rates of taxation on energy products between regions, provided that those rates comply with the minimum rates laid down in that directive, and the second interpretation, advocated by the appellant and the Commission, to the effect that the obligation to comply with a uniform level of taxation throughout the territory of a Member State for the same product, which stems from Article 5 of Directive 2003/96, applies irrespective of compliance with the minimum levels of taxation required by that directive.
42. For the following reasons, I take the view that the latter interpretation should be favoured.
43. In the first place, it must be recalled that, even if the field of the taxation of energy products and electricity is only partly harmonised and Directive 2003/96 affords the Member States a degree of flexibility and leeway so that they can implement policies adapted to their national circumstances, the fact remains that that leeway has limits. It follows that the option afforded to the Member States of introducing differentiated rates of taxation, tax exemptions or reductions in excise duties can be implemented only if the conditions laid down in the relevant provisions of that directive are strictly observed. Without such limits, the directive would be entirely meaningless.
44. Article 5 of Directive 2003/96 does not derogate from that restrictive approach, since the very wording of that provision demonstrates the legislature’s intention to circumscribe the leeway available to the Member States to apply different rates for the same product, regardless of compliance with the minimum levels of taxation required by that directive. (19) Thus, contrary to what the Spanish Government argues, that directive does not give the Member States absolute freedom to set the differentiated rates of taxation which they deem appropriate by relying solely on the fact that the rate applied remains greater than the minimum rate required. Such an interpretation would entirely defeat the purpose of Article 5 of Directive 2003/96. I therefore agree with the view expressed by Advocate General Richard de la Tour in his Opinion in Commission v Italy (Contribution towards the purchase of motor fuel) (C‑63/19, EU:C:2020:596, point 82), namely that derogations from the principle of a single level of taxation for each product and for each use may be applied by a Member State only in the cases expressly provided for in Directive 2003/96.
45. It must be clarified, furthermore, that Article 5 is not the only provision of Directive 2003/96 allowing for disparities in matters of taxation within the same Member State. Article 19 of that directive authorises Member States to introduce differentiated rates of taxation by means of further exemptions or reductions for specific policy considerations, provided that the Council, acting unanimously on a proposal from the Commission, does not raise any opposition. It must be found, in that regard, that the Council has already authorised, under that provision, a number of reductions in excise duties for specific regions or areas within a Member State. (20)
46. Whereas the Commission and the appellant take the view that, in order to apply a differentiated rate in a particular region, a Member State must have recourse to Article 19 of Directive 2003/96 and apply for an authorisation under that provision, the Spanish Government, for its part, without taking a position on the need to obtain such authorisation, contends that the fact that reductions in levels of taxation have been authorised pursuant to Article 19 is sufficient, on its own, to show that that directive does indeed allow regional disparities.
47. Although it is not clear from the actual wording of Article 5 of Directive 2003/96 whether the authorisation system laid down in that provision covers only situations in which the differentiated taxation stems from an exemption or a reduction beyond the minimum rates or whether Article 5 also encompasses situations such as that at issue in the main proceedings in which the differentiated regional tax remains greater than the minimum levels of taxation, the fact remains that, in any event, in order for a Member State to be able to rely on that possibility, that Member State is obliged to obtain the prior authorisation from the Council in accordance with Article 19 of that directive, which the Spanish Government has failed to do in the present case.
48. In the second place, it is necessary to examine the argument raised by the Spanish Government that Article 50ter of the Law on excise duties, as a manifestation of the political autonomy of the autonomous communities, as recognised by the Spanish Constitution and as protected by Article 4(2) TEU, (21) justifies the interpretation of Directive 2003/96 advocated by that government.
49. It should be borne in mind in that regard that the division of competences within a Member State benefits from the protection conferred by Article 4(2) TEU, under which the European Union must respect the national identity of the Member States, inherent in their fundamental structures, political and constitutional, including as regards local and regional self-government. (22) Furthermore, it is settled case-law of the Court that each Member State is free to allocate powers internally and to implement Community acts which are not directly applicable by means of measures adopted by regional or local authorities, provided that that allocation of powers enables the Community legal measures in question to be implemented correctly. (23)
50. It must be observed, however, that none of the provisions of Directive 2003/96, including Article 5 thereof (even interpreted in the meaning proposed in point 44 of this Opinion), can call into question the principles recognised under Article 4(2) TEU. By laying down a series of provisions allowing Member States to depart, subject to certain conditions, from the minimum rates prescribed in that directive, that directive seeks not only, in essence, to take into consideration the fiscal traditions of the Member States but to enable them also to implement policies adapted to their national circumstances. (24) I am therefore of the view that no Member State may rely on the protection conferred by Article 4(2) TEU or on, inter alia, its domestic arrangements and the division of competences to justify an infringement of EU law. Moreover, any differentiation in fiscal matters at regional level, irrespective of its scale, could not be interpreted as a manifestation of the national identity of a Member State or justified unconditionally on that basis. It could not be otherwise unless, as the case may be, each autonomous region had, pursuant to the Constitution, the option of establishing an entirely different tax regime, which it defined autonomously.
51. In the third place, it must be observed that Directive 2003/96 seeks to promote the proper functioning of the internal market in the energy sector. In addition, while that directive does, in principle, allow for the possibility of there being different rates between Member States (provided that the minimum rates are respected), affording each Member State the option of applying differentiated rates within its national territory and in its different regions, even where those rates comply with the minimum rates, without any limits or supervisory mechanism, would be likely to impair the proper functioning of the internal market by fragmenting it further, thus jeopardising the free movement of goods, and making it impossible moreover to exclude the risk of tax fraud.
52. In the fourth place, Directive 2008/118, which governs the general arrangements for excise duties, provides, in Article 1(2) thereof, that excise goods may be subject to other indirect taxes. That article, combined with a number of provisions of Directive 2003/96, which explicitly leaves to the Member States the option of imposing other taxes on electricity and energy products, (25) allows, according to the Spanish Government, an additional tax to be levied, like the IEH.
53. However, it must be recalled that, while Article 1(2) of Directive 2008/118 does leave to the Member States the option of levying indirect taxes on excise goods other than excise duties, such taxes may be levied only if two cumulative conditions are satisfied. First, such taxes must be levied for specific purposes and, second, those taxes must comply with the EU tax rules applicable for excise duty or VAT as far as determination of the tax base, the calculation of the tax, chargeability and the monitoring of the tax are concerned. (26)
54. Turning, more specifically, to the criterion relating to the specific purpose, it follows from settled case-law of the Court that, while there is no need for the revenue from an additional tax to be assigned to the specific purpose pursued, the tax in question must still be designed, in terms of its structure, in particular the taxable item or the tax rate, in such a way that it influences the behaviour of taxpayers in a manner that allows the specific purpose invoked to be achieved, for example by taxing heavily the products concerned in order to discourage their consumption or by encouraging the use of other products whose effects are less harmful vis-à-vis the objective pursued. (27)
55. However, it is not possible to establish, on the basis of the information in the documents before the Court, the extent to which the revenue collected by the additional tranche of taxation is intended for a specific purpose or whether that tax is structured in a way which allows the specific purpose invoked to be achieved (assuming that such a purpose exists). That does not, however, appear to be the case with the IEH. As is apparent from the written observations submitted by the Spanish Government, the regional rate of the IEH is intended to finance the competences of the autonomous communities generally, so that they are able subsequently, to use that revenue on a regional scale in the areas chosen by those communities.
56. In the fifth and final place, the recent case-law of the Court on the application of Directive 2003/96 appears to run counter to the application of a tax differentiated by territory within a single Member State. (28) While Directive 2003/96 grants Member States the option of introducing differentiated rates of taxation, tax reductions and tax exemptions, the case-law of the Court requires that that discretion enjoyed by the Member States under the relevant provisions of that directive (including Article 5 thereof) is exercised in compliance with EU law and its general principles and, in particular, in compliance with the principle of equal treatment. (29) This is, moreover, apparent from the very wording of Article 5 of that directive, which expressly provides that differentiated taxes may be applied ‘provided that … they are compatible with [EU] law’.
57. It must be observed in that regard that the principle of equal treatment requires that comparable situations must not be treated differently and that different situations must not be treated in the same way unless such treatment is objectively justified. (30) Save where that situation is objectively justified, which does not appear to be the case here, the a priori comparable situation of two liable producers of mineral oils in the same Member State could not be treated equally if they are required to pay different levels of taxation solely on the basis of a geographic criterion, without that treatment being objectively justified.
58. In the light of all of the foregoing, the sole question referred for a preliminary ruling by the referring court must be answered to the effect that Directive 2003/96, in particular Article 5 thereof, must be interpreted as precluding Member States from providing for a differentiated regional rate of excise duty on hydrocarbons which would entail the application of a different regional tax for the same product and the same use, other than in the cases listed exhaustively in that directive.
V. Conclusion
59. In the light of the foregoing considerations, I propose that the Court answer the sole question referred for a preliminary ruling by the Tribunal Supremo (Supreme Court, Spain) as follows:
Council Directive 2003/96/EC of 27 October 2003 restructuring the Community framework for the taxation of energy products and electricity, in particular Article 5 thereof,
must be interpreted as precluding Member States from providing for a differentiated regional rate of excise duty on hydrocarbons which would entail the application of a different regional tax for the same product and the same use, other than in the cases listed exhaustively in that directive.