This article critically examines the European Court of Justice's (ECJ) decision in the TimePartner case and its implications for labour market integration in the context of temporary agency work. The author supports the ECJ's position on the rule-exception relationship within Directive 2008/104/EC, emphasising equal treatment for temporary agency workers. The analysis explores the alignment between the ECJ's approach and the Directive's goal of creating a non-discriminatory, transparent, and proportionate framework for worker protection. Within the German legal landscape, where there has been reluctance to implement the Directive, complex collective agreements have led to substantial remuneration disparities between regular employees and temporary agency workers. The absence of statutory regulations on overall protection for temporary agency workers, coupled with reluctance on the part of courts to intervene in collective agreements, presents challenges for labour market integration. The article also addresses the assumption of an inherent warranted correctness of collective agreements and its potential implications for EU law enforcement, recognising this may limit the judicial review of collective agreements for compliance with EU Directives, potentially undermining EU law effectiveness. In conclusion, this analysis sheds light on the consequences of the ECJ's TimePartner case decision, particularly in Germany, and suggests the need for more detailed, industry-specific collective agreements to better meet the Directive's requirements.