The war in Ukraine has brought about an unprecedented change in the way the European Union addresses migration-related issues. Following the invasion of Ukraine by Russian forces in late February 2022, the Council of the European Union adopted an Implementing Decision establishing the existence of a mass influx of displaced persons from Ukraine within the meaning of Article 5 of Council Directive 2001/55/EC, for the first time activating its temporary protection mechanism. While the Directive’s provisions reflect the founding principles of the European Union, the specific vulnerabilities of international migrants require suitable social provisions to afford them a standard of living as required to ensure their health and well-being for the duration of the protection provided by the Directive. The purpose of this article is to discuss the nature of the challenges arising from this first application of the ‘Temporary Protection Directive’, as well as the impact of these challenges on the Directive’s efficacy and on the scope of the protection for the displaced persons covered by it. It argues, first, that the joint interpretation of the Directive and the Council Decision significantly limits the personal scope of the protection, leaving certain categories of migrants behind. The paper then goes on to examine the Directive’s substance and suggests that a broad interpretation of its social protection provisions reveals new difficulties regarding the financing and sustainability of this protection and its sustainability.