Question: What is the highest court in the organization that's seen as a great power in addition to member countries?

full_context: Document 1: G20: Membership of the G20 consists of 19 individual countries plus the European Union (EU). The EU is represented by the European Commission and by the European Central Bank. Collectively, the G20 economies account for around 85% of the gross world product (GWP), 80% of world trade (or, if excluding EU intra-trade, 75%), two - thirds of the world population, and approximately half of the world land area.
Document 2: European Union law: Fourth, national courts have a duty to interpret domestic law "as far as possible in the light of the wording and purpose of the directive". Textbooks (though not the Court itself) often called this "indirect effect". In Marleasing SA v La Comercial SA the Court of Justice held that a Spanish Court had to interpret its general Civil Code provisions, on contracts lacking cause or defrauding creditors, to conform with the First Company Law Directive article 11, that required incorporations would only be nullified for a fixed list of reasons. The Court of Justice quickly acknowledged that the duty of interpretation cannot contradict plain words in a national statute. But, fifth, if a member state has failed to implement a Directive, a citizen may not be able to bring claims against other non-state parties, but can sue the member state itself for failure to implement the law. So, in Francovich v Italy, the Italian government had failed to set up an insurance fund for employees to claim unpaid wages if their employers had gone insolvent, as the Insolvency Protection Directive required. Francovich, the former employee of a bankrupt Venetian firm, was therefore allowed to claim 6 million Lira from the Italian government in damages for his loss. The Court of Justice held that if a Directive would confer identifiable rights on individuals, and there is a causal link between a member state's violation of EU and a claimant's loss, damages must be paid. The fact that the incompatible law is an Act of Parliament is no defence.
Document 3: European Union law: The concept of legal certainty is recognised one of the general principles of European Union law by the European Court of Justice since the 1960s. It is an important general principle of international law and public law, which predates European Union law. As a general principle in European Union law it means that the law must be certain, in that it is clear and precise, and its legal implications foreseeable, specially when applied to financial obligations. The adoption of laws which will have legal effect in the European Union must have a proper legal basis. Legislation in member states which implements European Union law must be worded so that it is clearly understandable by those who are subject to the law. In European Union law the general principle of legal certainty prohibits Ex post facto laws, i.e. laws should not take effect before they are published. The doctrine of legitimate expectation, which has its roots in the principles of legal certainty and good faith, is also a central element of the general principle of legal certainty in European Union law. The legitimate expectation doctrine holds that and that "those who act in good faith on the basis of law as it is or seems to be should not be frustrated in their expectations".
Document 4: Great power: With continuing European integration, the European Union is increasingly being seen as a great power in its own right, with representation at the WTO and at G8 and G-20 summits. This is most notable in areas where the European Union has exclusive competence (i.e. economic affairs). It also reflects a non-traditional conception of Europe's world role as a global "civilian power", exercising collective influence in the functional spheres of trade and diplomacy, as an alternative to military dominance. The European Union is a supranational union and not a sovereign state, and has limited scope in the areas of foreign affairs and defence policy. These remain largely with the member states of the European Union, which include the three great powers of France, Germany and the United Kingdom (referred to as the "EU three").
Document 5: Great power: Japan and Germany are great powers too, though due to their large advanced economies (having the third and fourth largest economies respectively) rather than their strategic and hard power capabilities (i.e., the lack of permanent seats and veto power on the UN Security Council or strategic military reach). Germany has been a member together with the five permanent Security Council members in the P5+1 grouping of world powers. Like China, France, Russia and the United Kingdom; Germany and Japan have also been referred to as middle powers.
Document 6: Francovich v Italy: Francovich v Italy (1991) C-6/90 was a decision of the European Court of Justice which established that European Union member states could be liable to pay compensation to individuals who suffered a loss by reason of the member state's failure to transpose an EU directive into national law. This principle is sometimes known as the principle of state liability or "the rule in "Francovich"" in European Union law.
Document 7: European Union law: While the Treaties and Regulations will have direct effect (if clear, unconditional and immediate), Directives do not generally give citizens (as opposed to the member state) standing to sue other citizens. In theory, this is because TFEU article 288 says Directives are addressed to the member states and usually "leave to the national authorities the choice of form and methods" to implement. In part this reflects that directives often create minimum standards, leaving member states to apply higher standards. For example, the Working Time Directive requires that every worker has at least 4 weeks paid holidays each year, but most member states require more than 28 days in national law. However, on the current position adopted by the Court of Justice, citizens have standing to make claims based on national laws that implement Directives, but not from Directives themselves. Directives do not have so called "horizontal" direct effect (i.e. between non-state parties). This view was instantly controversial, and in the early 1990s three Advocate Generals persuasively argued that Directives should create rights and duties for all citizens. The Court of Justice refused, but there are five large exceptions.
Document 8: European Union law: To make new legislation, TFEU article 294 defines the "ordinary legislative procedure" that applies for most EU acts. The essence is there are three readings, starting with a Commission proposal, where the Parliament must vote by a majority of all MEPs (not just those present) to block or suggest changes, and the Council must vote by qualified majority to approve changes, but by unanimity to block Commission amendment. Where the different institutions cannot agree at any stage, a "Conciliation Committee" is convened, representing MEPs, ministers and the Commission to try and get agreement on a joint text: if this works, it will be sent back to the Parliament and Council to approve by absolute and qualified majority. This means, legislation can be blocked by a majority in Parliament, a minority in the Council, and a majority in the Commission: it is harder to change EU law than stay the same. A different procedure exists for budgets. For "enhanced cooperation" among a sub-set of at least member states, authorisation must be given by the Council. Member state governments should be informed by the Commission at the outset before any proposals start the legislative procedure. The EU as a whole can only act within its power set out in the Treaties. TEU articles 4 and 5 state that powers remain with the member states unless they have been conferred, although there is a debate about the Kompetenz-Kompetenz question: who ultimately has the "competence" to define the EU's "competence". Many member state courts believe they decide, other member state Parliaments believe they decide, while within the EU, the Court of Justice believes it has the final say.
Document 9: European Union law: The judicial branch of the EU has played an important role in the development of EU law, by assuming the task of interpreting the treaties, and accelerating economic and political integration. Today the Court of Justice of the European Union (CJEU) is the main judicial body, within which there is a higher European Court of Justice (commonly abbreviated as ECJ) that deals with cases that contain more public importance, and a General Court that deals with issues of detail but without general importance. There is also a Civil Service Tribunal to deal with EU staff issues, and then a separate Court of Auditors. Under the Treaty on European Union article 19(2) there is one judge from each member state, 28 at present, who are supposed to "possess the qualifications required for appointment to the highest judicial offices" (or for the General Court, the "ability required for appointment to high judicial office"). A president is elected by the judges for three years. Under TEU article 19(3) is to be the ultimate court to interpret questions of EU law. In fact, most EU law is applied by member state courts (the English Court of Appeal, the German Bundesgerichtshof, the Belgian Cour du travail, etc.) but they can refer questions to the EU court for a preliminary ruling. The CJEU's duty is to "ensure that in the interpretation and application of the Treaties the law is observed", although realistically it has the ability to expand and develop the law according to the principles it deems to be appropriate. Arguably this has been done through both seminal and controversial judgments, including Van Gend en Loos, Mangold v Helm, and Kadi v Commission.
Document 10: Greece: Greece is a democratic and developed country with an advanced high-income economy, a high quality of life and a very high standard of living. A founding member of the United Nations, Greece was the tenth member to join the European Communities (precursor to the European Union) and has been part of the Eurozone since 2001. It is also a member of numerous other international institutions, including the Council of Europe, NATO,[a] OECD, OIF, OSCE and the WTO. Greece, which is one of the world's largest shipping powers, middle powers and top tourist destinations, has the largest economy in the Balkans, where it is an important regional investor.
Document 11: Southern Europe: Italy became a major industrialized country again, due to its post-war economic miracle. The European Union (EU) involved the division of powers, with taxation, health and education handled by the nation states, while the EU had charge of market rules, competition, legal standards and environmentalism. The Soviet economic and political system collapsed, leading to the end of communism in the satellite countries in 1989, and the dissolution of the Soviet Union itself in 1991. As a consequence, Europe's integration deepened, the continent became depolarised, and the European Union expanded to subsequently include many of the formerly communist European countries – Romania and Bulgaria (2007) and Croatia (2013).
Document 12: European Union law: European Union law is applied by the courts of member states and the Court of Justice of the European Union. Where the laws of member states provide for lesser rights European Union law can be enforced by the courts of member states. In case of European Union law which should have been transposed into the laws of member states, such as Directives, the European Commission can take proceedings against the member state under the Treaty on the Functioning of the European Union. The European Court of Justice is the highest court able to interpret European Union law. Supplementary sources of European Union law include case law by the Court of Justice, international law and general principles of European Union law.
Document 13: Great power: Another important factor is the apparent consensus among Western great powers that military force is no longer an effective tool of resolving disputes among their peers. This "subset" of great powers – France, Germany, Japan, the United Kingdom and the United States – consider maintaining a "state of peace" as desirable. As evidence, Baron outlines that since the Cuban missile crisis (1962) during the Cold War, these influential Western nations have resolved all disputes among the great powers peacefully at the United Nations and other forums of international discussion.
Document 14: Great power: Milena Sterio, American expert of international law, includes the former axis powers (Germany, Italy and Japan) and India among the great powers along with the permanent members of the UNSC. She considers Germany, Japan and Italy to be great powers due to their G7 membership and because of their influence in regional and international organizations.  Various authors describe Italy as an equal major power, while others view Italy as an "intermittent great power" or as "the least of the great powers".
Document 15: European Union law: The primary law of the EU consists mainly of the founding treaties, the "core" treaties being the Treaty on European Union (TEU) and the Treaty on the Functioning of the European Union (TFEU). The Treaties contain formal and substantive provisions, which frame policies of the European Union institutions and determine the division of competences between the European Union and its member states. The TEU establishes that European Union law applies to the metropolitan territories of the member states, as well as certain islands and overseas territories, including Madeira, the Canary Islands and the French overseas departments. European Union law also applies in territories where a member state is responsible for external relations, for example Gibraltar and the Åland islands. The TEU allows the European Council to make specific provisions for regions, as for example done for customs matters in Gibraltar and Saint-Pierre-et-Miquelon. The TEU specifically excludes certain regions, for example the Faroe Islands, from the jurisdiction of European Union law. Treaties apply as soon as they enter into force, unless stated otherwise, and are generally concluded for an unlimited period. The TEU provides that commitments entered into by the member states between themselves before the treaty was signed no longer apply.[vague] All EU member states are regarded as subject to the general obligation of the principle of cooperation, as stated in the TEU, whereby member states are obliged not to take measure which could jeopardise the attainment of the TEU objectives. The Court of Justice of the European Union can interpret the Treaties, but it cannot rule on their validity, which is subject to international law. Individuals may rely on primary law in the Court of Justice of the European Union if the Treaty provisions have a direct effect and they are sufficiently clear, precise and unconditional.
ground_truth: The European Court of Justice
sub_queries: What organization is often seen as a great power in addition to member counties? Answer: European Union
Which court is the highest court in European Union ? Answer: The European Court of Justice