This thesis advances a relative justice approach to the judicial and non-judicial review of EU legal acts. It specifically compares the kind of justice, predominantly procedural in nature, delivered by the action for annulment before the EU Courts; appeal before the Board of Appeal of the European Chemical Agency and complaint to the European Ombudsman. By exploring the practical functioning of these mechanisms, the thesis seeks to determine whether non judicial review mechanisms can fill gaps in the EU system of justice caused by inherent shortcomings of EU judicial review. These shortcomings – the uncertain thoroughness and limited accessibility of judicial review – stem from a constant need to avoid overloading the EU Courts with complex cases and shifting on them too much responsibility for the substance of EU law, rule and decision-making.