Miguel Pereira (Master’s student in European Union Law at the School of Law of the University of Minho)
1. Direct effect: paving the road for the European integration
On 5 February 1963, the Court of Justice of the European Union (“CJEU”) issued a judgment that would become a cornerstone of the European Union (“EU”), notwithstanding the fact that the substance of the matter under judgement was quite mundane: was the import duty applied to the import of a chemical component, used mostly to produce adhesive materials, contrary to Article 12 of the European Economic Community Treaty (“EEC Treaty”)?
In all likelihood, most of us would have gone by without ever reading the word “ureaformaldehyde” but fate, and mostly the Court, would have it another way. As it stands, the judgment of the Court in Case 26/62, commonly known as Van Gend & Loos (owing its designation to the plaintiff in the main action in the national court), introduced a new fundamental principle of EU Law, the principle of direct effect, which may be broadly defined as “the capacity of a provision of EU law to be invoked before a national court”. To this broad definition we might add that those provisions must confer rights or impose obligations on those that seek the recognition of direct effect of a given provision. The conditions under which direct effect might be conferred to a provision of EU law are specific and relate to the content and wording of the provision itself, the source of said provision and the nature of the parties in the dispute.
The significance of such a bold step cannot be understated, particularly if we keep in mind the date in which this judgment was issued, just six years after the signature of the EEC Treaty. From an International Law perspective, the ruling remains unrivaled, as André Nollkaemper notes, adding that, while direct effect is not unknown in jurisdictions outside the EU, “what fundamentally changed the discourse was that a sizeable group of states accepted that the direct effect of future rules of unknown content and scope was no longer under their exclusive control, but was determined by EU law.”
However, the meaning of this judgment cannot be circumscribed to its uniqueness as regards International Law. As it stands, direct effect implies, and has contributed to, the construction of the EU citizenship which the Treaties have set out to accomplish. The fact that EU citizens can enforce their rights as granted by the EU legal order against the Member States and their public authorities by having them directly apply within the territory of a Member State, even when that entails not applying a provision of national law, grants the EU citizenship actual substance. This is particularly evident, as Alessandra Silveira highlights, in the judgment in Case Baumbast, where the Court recognizes direct effect to Article 21(1) TFEU which grants EU citizens the right of free movement and residency within the territory of its Member States. The Court goes so far as to state that this right is not restricted to those EU citizens which are also migrant workers but is, in fact, independent of such pre-requisite.
The practical relevance of direct effect lays in its potential use in litigation before national courts. Direct effect entails the possibility of setting aside provisions of national law that are incompatible with EU law with the intent of applying the latter directly within the territory of a given Member State. This ability expands the usual scope of litigation and is essential to ensure the effective legal protection of EU citizens, as prescribed by Article 19(1) TEU.
In connection with direct effect, we intend to outline the core elements of a related principle, recognized by the CJEU in von Colson and Kamann, which provides that when applying national law, which falls within the scope of a directive of EU law (or a framework decision), the national court should do so, to the farthest extent possible, in light of the wording and purpose of the directive (or framework decision, as may be). This principle became known as the principle of interpretation in conformity with EU law or conforming interpretation and recent judgements of the Court have brought it to the forefront of the debate surrounding the direct effect of directives, particularly when the matter is raised in the context of a dispute between private parties.
As a final note, it is worth highlighting the interconnection of direct effect and the principle of conforming interpretation with the primacy and effectiveness of EU law – two other principles which the CJEU has extract from the Treaties (in particular, Article 4 TEU). The primacy and effectiveness of EU law consist on the obligation impending on Member States: 1) to assess the validity of EU law in reference not to national law but rather to EU law, requiring national bodies, in general, to give full effect to EU law in such a way that national law may not undermine such effect and, specifically, in given circumstances, to set aside any provision of national law that might be incompatible with EU law and 2) to “take any appropriate measure, general or particular, to ensure” full effectiveness of EU law (be it a provision of the Treaties or secondary legislation). The relationship between these principles is close to symbiotic as, more often than not, the primacy and effectiveness of EU law are contingent to direct effect or conforming interpretation.
The purpose of this essay is not to offer a comprehensive view of the matter (such an endeavor would not be possible within the strict confines of these pages) but rather to provide a reference guide through the CJEU’s case-law which constitutes the brick and mortar of the principle of direct effect and of the principle of conforming interpretation. Given the intended scope of the essay we also will not cover the full doctrine of these principles as laid out by the CJEU, rather focusing on its core elements and conceptual issues.
2. Arguments for and basic elements of direct effect: Van Gen & Loos
The dispute in Case 26/62 involved NV Algemene Transport- en Expeditie Onderneming van Gend & Loos, a distribution company, and the Netherlands Inland Revenue Administration, following the application by the latter of an import duty of 8% on an import of ureaformaldehyde by the former. By requesting a preliminary ruling, the Dutch court hearing the case asked the CJEU whether such import duty (applied following the entry into force in 1959 of certain amendments to the relevant national legislation which reclassified the chemical compound and resulted in a higher import duty being charged), was compatible with the EEC Treaty, particularly Article 12 – which laid out that Member States would abstain from increasing import duties in relation to imports from other Member States. The answer to this question, however, could only be of relevance if the EEC Treaty were to directly confer on Van Gend & Loos a right that it could enforce against the Dutch administration.
In its judgment, the Court decided not only that the import duty and the underlaying legislation was incompatible with the treaty obligation impending on the Kingdom of the Netherlands, as laid out in Article 12 EEC, but also that the prohibition of abstention from increasing import duties in trades between the Community’s Member States was to be construed as conferring a right on individuals, which national courts were bound to protect. In doing so, it called forth the EEC Treaty’s objective of establishing a Common Market, which it held to be beyond the scope of what a common international agreement between States would comprise. The Court then went further, admitting that the “community constitutes a new legal order of international law for the benefit of which the states have limited their sovereign powers (…) and the subjects of which comprise not only the Member States but also their nationals”. It contended, additionally, that the EEC Treaty provisions concerning preliminary rulings imply that it is within the Member States’ nationals capacity to invoke EU law in a national court and that affording clear recognition of their rights under EU law, in such a way that they could rely on them in national courts, would result in an “effective supervision” of the compliance by Member States with their obligations under the EEC Treaty.
On this basis, it recognizes that the treaties can directly confer rights upon individuals which, should they be sufficiently clear and unconditional (as was the case), produce direct effects in the legal order of the Member States.
While the judgement in Van Gend & Loos concerned the direct effect of a treaty provision, it has since become apparent that all legally binding acts of EU law are capable of being afforded direct effect, subject to the caveats laid out below. It is also clear that, apart from rights arising from directives (vide infra, section 3.1), direct effect can be raised against the State and State entities (vertical direct effect), and against individuals (horizontal direct effect).
2.1. Clear and unconditional provisions: Barber, Reyners and Lütticke
Van Gend & Loos, in its appreciation of Article 12’s capacity of producing direct effect, provided additional criteria – namely, that the provision contained a negative obligation (that is to say, one of abstention), that it was not “qualified by any reservation on the part of state” and that it did not require any additional implementing measure. These requirements were subsequently loosened – though we would argue that the last two conditions have, in essence, been condensed in the unconditionality requirement.
In Barber, the Court further explains what is to be understood by a “clear” provision. The particular case concerned the interpretation of Article 119 EEC which established the principle of equal pay for men and women. From this Judgment it follows that for a provision to be sufficiently clear, the right it confers should be determined in reference to the article in question, without the need for national or EU measures to “define them with greater precision in order to permit their application”. The Court considered in the case under appreciation that the content of the right was clear enough as it referred to the criteria of equal pay for equal work when defining the principle.
In what regards the unconditionality requirement, Lütticke and Reyners provided additional clues as to when such characteristics are present. In both cases the judgment concerned Treaty provisions that were conditional to a transitional period, during which Member States were obliged to purge any provision of national law that was incompatible with the prohibitions in the Treaty (prohibition of imposition of different taxation on national products and those imported from other Member States and prohibition of discrimination based on nationality, respectively), and to fully comply with said prohibitions after the transitional period had elapsed – which had happened in both cases. The Court held in Lütticke that where an obligation impending on Member States is not qualified by any condition or subject in its effects to any implementing measures, either at EU or national level, it is considered to be complete and legally perfect, adding that where the Treaty provides for a specific period for Member States to give them effect, once that period has elapsed, the provision is liable to produce direct effect. This is confirmed in Reyners, where the obligation was not to purge national provisions incompatible with EU law by a specific deadline but, instead, to adopt specific measures to progressively implement a right recognized in the treaty (that of freedom of establishment). This concept of determining direct effect upon the expiration of a deadline will be replicated, as we will see, in what regards direct effect of directives. Absent any deadline for implementation, and provided that the requirements of clarity and unconditionality are met, Treaty provisions are not subject to any temporal restrictions in order to produce effects.
3. Direct effect of directives: Van Duyn
We have, so far, focused on direct effect with regard to treaty provisions which, following Van Gend & Loos, and subsequent case-law (not limited to that which has been mentioned in the preceding section), has become well established and accepted. On the contrary, as regards directives, the same cannot be said as there are still some unanswered questions, particularly in disputes opposing private parties (vide infra, section 3.1).
The matter of whether provisions contained in directives were susceptible of producing direct effect was put to rest in van Duyn. The case opposed Yvonne van Duyn, a Dutch national, to the Home Office of the United Kingdom (“UK”) and the matter concerned the denial of entry of the former into the UK. The national court asked the CJEU to rule on whether Article 48 EEC (which provided for the freedom of movement of workers and, in connection, the prohibition of discrimination on the basis of nationality as regards employment, remuneration and other conditions of work and employment) and Council Directive 64/221/EEC were to be interpreted as having direct effect. The CJEU ruled that Article 48 EEC was indeed capable of producing direct effects inasmuch as it fulfilled the aforementioned criteria (vide supra, sections 2 and 2.1). Furthermore, the Court went on to rule that the relevant provision contained in the directive, namely Article 3(1), was to be interpreted as having direct effect as it embodied a precise and unconditional obligation on the part of the Member States.
The CJEU based this assertion on an extensive interpretation of Article 189 CEE (now, Article 288 TFEU), stating that the fact that only regulations were expressly described as being directly applicable in the Member States’ territory did not preclude the possibility of the other legal acts being accorded a similar effect, adding, further to that, that “it would be incompatible with the binding effect attributed to a directive” to preclude its susceptibility of having direct effect. Considering the effectiveness of EU law, which Member States are bound to uphold, “the useful effect of such an act would be weakened if individuals were prevented from relying on it before their national courts and if the latter were prevented from taking it into consideration as an element of community law”. It anchors its argument in two other elements, one of legal certainty which provides that nationals of Member States should be able to rely on the obligation imposed on the latter even where that obligation was laid down on a legal act which does not entail direct effect in its entirety, and another which it used in Van Gend & Loos, that is to say the extensive interpretation of Article 177 CEE, on preliminary rulings (vide supra, section 2.).
3.1. Limits to the direct effect of directives: Becker and Marshall
Given the specificity of directives as legal instruments, the CJEU was soon called upon to provide further clarifications on the scope of direct effect when it concerned these legal acts. In that sense, Becker provides some insights as to when direct effect of a provision of a directive might be raised as well as the latitude of the unconditionality requirement, particularly relevant in this context as directives leave the means by which the results envisaged by the directive are to be achieved. In that regard, the Court has established that the direct effect of a provision contained in a directive is only to be recognized once the deadline for transposition into national law has passed and has clarified that, while Member States might be given some discretion in implementing a directive in national law, such discretion is not to preclude the direct effect of provisions “which owing to their particular subject-matter are capable of being severed from the general body of provisions and applied separately”, provided they are sufficiently clear and, otherwise, unconditional.
The CJEU has consistently refused to recognize horizontal direct effect of directives, basing that stance on a literal interpretation of Article 288 TFEU (former Article 189 EEC, according to which “A directive shall be binding (..) upon each Member State to which it is addressed”), according to which directives are to bind only the Member States. This doctrine was introduced with Marshall and has been reaffirmed in subsequent cases. As Paul Craig has noted, considering the more extensive interpretation the Court has given other treaty articles specifically addressed to Member States, the fact that Article 288 does not expressly limit its effects only to Member States, and the Court’s eagerness to recognize exceptions to this rule (vide infra section 4) when there were additional elements besides the directive in question arguing for the recognition of direct effect, this textual argument is wobbly at best. In the case under appreciation, the dispute was between an individual and a public authority so the Court took the chance to add that, while direct effect is to be recognized only in relation to the Member States, it can be raised against them regardless of the capacity in which they are acting, even if the specific body has no say over the correct and timely transposition of a directive.
In the ensuing sections we will have a chance to explore the methods that the CJEU has designed to mitigate the effects of this ruling but for the moment it suffices to say that, while horizontal direct effect of directives is precluded, the recognition of direct effect in proceedings opposing an individual to the State might entail negative consequences to third parties, so long as the obligation impending on the Member State in accordance with a directive is not directly linked to the performance of said third party (Fratelli Constanzo, 203/88, paragraphs 28-33 and Judgment of the Court of 7 January 2004, Wells, C-201/02).
4. Circumventing Marshall: conforming interpretation, general principles of law and Member State liability
4.1. Conforming interpretation: von Colson and Marleasing
In von Colson, taking into consideration those situations where a given provision of a directive is not sufficiently clear and unconditional and having regard to the need to ensure the effectiveness of EU law, the CJEU recognized the principle of conforming interpretation, according to which “national courts are required to interpret their national law in the light of the wording and the purpose of the directive in order to achieve the result” envisaged by the directive. This obligation was distilled by the Court from the obligation to achieve the results envisaged by the directive and the principle of sincere cooperation through the extension of the obligation impending on Member States – the obligation to adopt all appropriate measure, whether general or particular, to ensure the full effectiveness of EU law – to all the authorities of Member States, including their courts.
While the case in von Colson concerned a dispute between an individual and a Member State authority, the CJEU soon had the chance to extend this principle to those involving only private parties. It did so with the purpose, or at least the result, of easing the effects that the Marshall ruling entailed, so as to grant some form of relief whenever direct effect was not capable (due to the nature of the dispute) of setting aside a provision of national law incompatible with EU law.
As such, in Marleasing, the CJEU confirms that conforming interpretation is to extend to relations between private individuals. If further confirms that the obligation impending on national courts to interpret national law in conformity with EU law is not restricted to those provisions which seek to transpose a directive but actually extends to national provisions that were adopted before the directive in question.
Subsequent cases, which we will recall in this section, laid down the framework and the limits to this obligation. As it stands, this principle requires the national courts “to do whatever lies within their jurisdiction, taking the whole body of domestic law into consideration and applying the interpretative methods recognized by domestic law, with a view to ensuring that the directive in question is fully effective and achieving an outcome consistent with the objective pursued by it” (Adeneler). This exercise is, however, bound by the limits imposed by the general principles of law, namely those of legal certainty and non-retroactivity and must not result in an interpretation of national law contra legem or, in the context of criminal proceedings, result in the determination or aggravation of criminal liability (Pupino and Nijmegen). The Court has expanded the principle to cover also incompatible national case-law (Popławsk). Finally, the obligation to interpret in conformity with EU law is raised only when the deadline for the transposition of the directive has passed, notwithstanding the fact that, in the period between this deadline and the date of entry into force of the directive (or, alternatively, when they have specific addressees and are not published in the Official Journal, on the date that they are notified to them), Member States’ courts are to abstain from “interpreting domestic law in a manner which might seriously compromise, after the period for transposition has expired, attainment of the objective pursued by that directive” (Adeneler).
4.2. General principles of law: Mangold, Kücükdeveci and AMS
In another attempt to limit the adverse consequences of the Marshall case-law, the CJEU in Mangold held that general principles of law are to be regarded as having direct effect, even when they do not find express recognition in the treaties and must be inferred from instruments of international law and the constitutional traditions of Member States, and the matter is raised in the context of a dispute between private parties.
In Kücükdeveci, the Court confirmed the ruling it issued in Mangold and considered a fundamental right enshrined in the Charter of Fundamental Rights of the European Union (“the Charter”) to be a general principle of law and, as such, considering the specific characteristics of the fundamental right in question, capable of producing direct effect.
In 2014, nine years following Mangold, the Court, in the judgment of AMS, took a step back in this line of case-law, considering that not all fundamental rights contained in the Charter, due to their specific construction necessarily linking them to implementing measures at EU and national levels, are capable of producing direct effect through the method designed in Kücükdeveci .
4.3. Member State liability: Francovich
Notwithstanding the lengths to which the CJEU has gone in order to minimize the lack of horizontal direct effect of directives, it has often proved impossible to apply the approaches and principles laid out in the preceding subsections. In those situations, where an individual sees their rights (as conferred by EU law) infringed due to lacking or faulty transposition of a directive, an infringement attributable to a Member State’s action (or lack thereof), the Court established, as a last resort, the possibility for individuals to hold Member States liable for said breaches. It did so in Francovich, establishing the necessary conditions for Member State liability to apply: 1) the breached provision should be one that grants rights to individuals, 2) the content of those rights must identifiable and 3) there should be a causal link between the Member State’s conduct and the loss and damage suffered by the private parties.
5. Concluding remarks: rethinking the primacy of EU law, conforming interpretation and direct effect
The development of the principle of direct effect has been a staple of European integration, recognizing the EU citizens as a driving force to attain the results envisaged by the treaties and empowering them to protect and further expand their “legal heritage”, in the expression coined in Van Gend & Loos. While some have reproached the Court for assuming a role that goes beyond what the treaties envisioned for it, the fundamental part it played in specifically lethargic phases of the EU integration cannot be denied, nor the result which it attained – an Europe more interconnected than it has ever been.
Notwithstanding that, it holds true that the doctrine of direct effect raises, still to this day, some issues. In particular – as highlighted (vide supra, sections 3 and 4) – in what regards the horizontal direct effect of directives. We stand with Paul Craig when he identifies issues with the recourse to the legal certainty argument to justify the denial of such effect to directives. The author, from a very practical standpoint, critiques (among other things) the lack of certainty which conforming interpretation might entail even for legal experts, let alone the common citizen. Where conforming interpretation is to be made use of in place of direct effect, individuals/private parties must try to divine what the conforming interpretation of national law might be upon review by a national judge, instead of relying on a specific provision from a directive which might determine a specific result.
Recent developments in the CJEU’s case law have, however, shifted the focus from direct effect to conforming interpretation. In Maribel Dominguez the Court unassumingly, in an almost tentative manner, provides that the question of whether a provision entails direct effect is secondary to that of whether it is possible to interpret it in conformity with EU law. This shift is confirmed in Popławski and subsequent case law, where the Court clearly links the obligation to interpret national law in conformity with EU law with the principle of primacy of EU law, affirming this interpretative obligation as one of the main mechanisms that ensures compliance with this principle. This option to elevate conforming interpretation to the status of first gatekeeper of the primacy of EU law, in addition to the issues highlighted in the preceding paragraph, may have the unintended result of undermining one of the CJEU’s main missions: that of ensuring the consistent and uniform interpretation of EU law across the Member States’ territories. Given that conforming interpretation seeks to adapt the interpretation of national law to one which leads to a result compatible with the objective envisaged by a specific EU law provision, it relies heavily on the assumption that: 1) the specific objective sought by EU law is always clearly stated or easily apprehensible; and 2) that the objective envisaged by EU law is not in itself susceptible of being interpreted differently. If we factor in the obligation to take the whole body of national laws and interpretative methods recognized by national law, it is reasonable to assume that the same provision of EU law might be interpreted differently across the whole of the EU, producing uneven results and further contributing to legal uncertainty. From an observer’s standpoint, it seems fair to ask: would not direct effect, which would lead the national court to apply the EU law provision in place of the conflicting national law, reduce the aforementioned unevenness of results and legal uncertainty?
From the foregoing, it seems clear that the tale of direct effect and conforming interpretation is still unfolding, as Alessandra Silveira and Sophie Perez note, in reference to the direct effect of fundamental rights contained in the Charter, following its ascension to Treaty status. It will be up to the individual litigants, national courts, Member States, Advocates General and Judges at the CJEU to play the main role in it and drive these principles along with the European integration.
 For the purpose of this essay and for ease of reference we will use this abbreviation and the expression “the Court” interchangeably. The CJEU is composed of two chambers, the Court of Justice and the General Court, each with different responsibilities in the interpretation and application of EU law. The Court of Justice is the one responsible for the issuance of preliminary rulings as laid out in Article 267 TFEU so, and again for the purpose of this essay, all references to the CJEU or the Court should be construed as referring to the Court of Justice.
 For a detailed description of the matter under appreciation, see Judgment of 5 February 1963, Van Gend & Loos, 26/62, ECLI:EU:C:1963:1, paragraphs 1 through 13.
 Paul Craig and Gráinne de Búrca, EU Law: Text, Cases and Materials (5th ed., Oxford: Oxford University Press, 2011).
 Alessandra Silveira and Sophie Perez, “De Van Gend & Loos a Maribel Domingues – reequacionando o efeito direto das disposições europeias à luz das dinâmicas da integração” in Estudos em Comemoração dos 20 anos da Escola de Direito da Universidade do Minho (Coimbra: Coimbra Editora, 2014), 15.
 André Nollkaemper, “The Duality of Direct Effect of International Law”, European Journal of International Law, Volume 25, Issue 1 (2014), 105–125, https://doi.org/10.1093/ejil/cht085. The author reviews the cases of direct effect of International Law outside the EU which, while increasing in number, show no indication of a system of direct effect similar to the one in the EU.
 Rui Manuel Moura Ramos, “A cidadania da União: caracterização, conteúdo e desenvolvimento” in Estudos de Direito da União Europeia (1st ed., Coimbra: Coimbra Editora, 2013), 229-260.
 Alessandra Silveira, “Cidadania europeia e direitos fundamentais”, Alessandra Silveira, Mariana Canotilho and Pedro Froufe (coords.), Direito da União Europeia – Elementos de Direito e Políticas da União (Coimbra, Almedina, 2016), 31-33 and Alessandra Silveira, “Cidadania social na União Europeia – quo vadis? Avanços e recuos entre forças de coesão e fragmentação”, Eduardo Paz Ferreira (coord.), União Europeia – reforma ou declínio (Lisbon: Editora Nova Vega, 2016), 299-300.
 Alessandra Silveira, “Cidadania europeia e direitos fundamentais”, 32 and Alessandra Silveira, “Cidadania social na União Europeia – quo vadis?”, 299.
 On effective judicial protection, see Joana Covelo de Abreu, “An approach to today’s EU constitutionality control – understanding this EU inter-jurisdictional phenomenon in light of effective judicial protection” in UNIO – EU Law Journal. Vol. 3, No. 2 (2017), 104-124, particularly pages 105-107.
 See, inter alia, Judgment of 16 June 2005, Pupino, C-105/03, ECLI:EU:C:2005:386 and Judgment of 24 June 2019, Popławski, C-573/17, ECLI:EU:C:2019:530.
 For an analysis of the interconnection of these principles and how the CJEU drew them from the principle of sincere cooperation as enshrined in Article 4 TEU, see Alessandra Silveira, Princípios de direito da União Europeia: Doutrina e Jurisprudência (Lisboa: Quid Juris?, 2011), 103-128.
 Paul Craig and Gráinne de Búrca, EU Law, 256.
 Article 4 (3) TEU.
 Paul Craig and Gráinne de Búrca, EU Law, 190. For direct effect of regulations and decisions, which will not be covered in this essay, see pp. 190 and 191 of the referenced work.
 Paul Craig and Gráinne de Búrca, EU Law, 186.
 Yvonne van Duyn was a Scientology follower and at the time in which the events unfolded the UK government was of the view that Scientology was to be considered as to be against public order and took steps to deny entry of foreign nationals that were known to be connected to the Church of Scientology..
 See, inter alia, Judgment of the Court of 14 July 1994, Dori, C-91/92, ECLI:EU:C:1994:292, paragraph 20 and Judgment of the Court of 8 October 1987, Nijmegen, 80/86, paragraph 9.
 Paul Craig, “The Legal Effect of Directives: Policy, Rules and Exceptions” in European Law Review, Volume 34, Issue 3, 2009, 351-352, accessed through: https://www.researchgate.net/publication/228183861_The_Legal_Effect_of_Directives_Policy_Rules_and_Exceptions, on the 15 January 2021.
 For further developments on the issue, see Alessandra Silveira and Sophie Perez, “De Van Gend & Loos a Maribel Domingues”, 21-26.
 Paul Craig and Gráinne de Búrca, EU Law, 188, where the authors allude to the phase following the Luxembourg Accords, regarding it as “legislative sclerosis”.
 The author reviews all the policy points and arguments put forth to deny horizontal direct effect of directives, highlighting the many difficulties that the Marshall case law has brought about. Paul Craig, “The Legal Effect of Directives”, 360-364.
See, inter alia, Judgment of 19 November 2019, A. K. and Others, C-585/18, ECLI:EU:C:2019:982, paragraphs 156-160; Judgment of 19 December 2019, Deutsche Umwelthilfe eV, C-752/18, ECLI:EU:C:2019:1114, paragraphs 39-42; Judgment of 15 April 2021, Braathens Regional Aviation, C-30/19, ECLI:EU:C:2021:269, paragraph 58.
 Alessandra Silveira and Sophie Perez, “De Van Gend & Loos a Maribel Domingues”, 34-37.
Picture credits: hpgruesen