The primary role of the ECJ is to ensure that EU law is interpreted and applied uniformly across all EU member states. This helps to maintain the integrity and effectiveness of the EU legal system.

The principle of legality is a fundamental principle of judicial review in the EU. It requires that all EU acts must be based on a legal basis in the EU treaties or other sources of EU law.

The principle of proportionality requires that EU measures must be necessary and appropriate to achieve their objectives. This means that the measures must be proportionate to the aims they seek to achieve and must not impose excessive burdens on individuals or organizations.

Individuals and organizations seeking to challenge EU acts may have access to a range of remedies, including annulment of the EU act, compensation for damages caused by the EU act, and injunction to prevent the implementation of the EU act.

National courts play a crucial role in the system of judicial review in the EU. They are responsible for enforcing EU law in their respective countries, referring questions of EU law to the ECJ for a preliminary ruling, and interpreting EU law in accordance with the rulings of the ECJ.

Van Gend en Loos v Nederlandse Administratie der Belastingen, Costa v ENEL, and Francovich v Italy are all significant cases in the development of judicial review in the EU. These cases established important principles and precedents that have shaped the current system of judicial review in the EU.

The principle of direct effect is a fundamental principle of EU law that allows individuals and organizations to directly enforce EU law in national courts. It also requires national courts to interpret national law in conformity with EU law and prohibits national courts from applying national laws that conflict with EU law.

The Advocate General plays a crucial role in the judicial review process before the ECJ. They provide an independent opinion on the case, represent the interests of the European Commission, and assist the judges in their deliberations.

Individuals and organizations can bring various types of judicial review actions before the ECJ, including action for annulment, action for failure to act, and action for damages.

The European Parliament plays a role in the system of judicial review in the EU by holding the European Commission accountable for its actions. The Parliament can initiate infringement proceedings against member states for failing to comply with EU law, but it cannot bring legal challenges against EU acts before the ECJ.

The preliminary reference procedure is the legal doctrine that allows national courts to request a preliminary ruling from the ECJ on questions of EU law. This procedure ensures that EU law is interpreted and applied uniformly across all EU member states.

The principle of supremacy is a fundamental principle of EU law that establishes the primacy of EU law over national law. It requires national courts to give precedence to EU law over national law and prohibits national courts from applying national laws that conflict with EU law.

The principle of non-intervention is a limitation on the scope of judicial review in the EU. It prohibits the ECJ from intervening in matters that are primarily within the competence of the member states.

The legal doctrine that allows individuals and organizations to seek compensation for damages caused by EU acts is known as non-contractual liability. This doctrine imposes liability on the EU for damages caused by its acts or omissions.

The system of judicial review in the EU is a mixed system that combines elements of both centralized and decentralized systems. The ECJ plays a central role in the system, but national courts also have a significant role in enforcing and interpreting EU law.