Which institution primarily ensures EU laws are obeyed across different countries?

The Court of Justice of the European Union (CJEU) is primarily responsible for ensuring that EU laws are interpreted and applied uniformly across all member states. Its role is pivotal in maintaining the rule of law within the EU, and it adjudicates disputes between member states, EU institutions, and individuals regarding the interpretation and application of EU law.

The court's judgments ensure that EU regulations and directives are enforced consistently, which helps to prevent discrepancies among member countries that could arise from different interpretations of the law. This function is essential for the functioning of the internal market and for promoting integration among member states.

Other institutions play important roles within the EU, but they do not primarily focus on legal compliance. For example, the European Commission proposes legislation and enforces EU laws but is not the final arbiter when disputes about the law arise. The European Parliament represents the interests of EU citizens and has legislative power, but it does not interpret or enforce laws. The European Court of Auditors oversees financial management but does not have a mandate to ensure legal compliance with EU law.