This article analyzes the ascent of immigrant-related policies in the European Union by identifying the most important actors influencing this process through an examination of key developments such as the Tampere European Council and the Amsterdam Treaty which paved the way for the adoption of Directive 2003/109/EC on the status and rights of thirdcountry nationals. In doing so, the key question to be discovered is the role of the EU with regards to immigrant integration by investigating a key European-level instrument as the case study, namely the adoption of Directive 2003/109/EC which is the most recent and relevant legislation establishing the status of third-country nationals in Europe. By examining whether the adoption of this Directive has led to any progress in terms of the rights of third-country nationals in Germany and the Netherlands, I try to assess whether the adoption of the Directive may be explained with the supranationalist view that the Commission has a strong supranational role as a political entrepreneur that promotes common norms and values, or it is a reflection of the prevalence of liberal intergovernmentalism and the rationalist motivations of the Member States to promote their interests when reaching a final compromise. The conclusions show that Member States choose to cooperate in these areas mainly because of their socioeconomic concerns such as restricting the increasing numbers of asylum, low-skilled immigration, the goal of global competitiveness and attracting qualified labor force. The preservation of these interests and the subordination of immigrant rights to national concerns reveal that Member States negotiate European policies by almost exclusively focusing on the distribution of gains unlike suggested by the supranational perspective which argues that negotiations are concerned with achieving an efficient policy outcome. Keywords: Immigration, Immigrant Integration, Third-Country National, Supranationalism, Liberal intergovernmentalism.