In April 2019 the European Parliament adopted its position on the so-called Mobility Package, a set of proposals for new rules for the transport sector within the European Union. Ever since the Mobility Package was first laid forward by the European Commission in 2017, it has been a contentious issue both within and outside of the European institutions and has often been framed as a conflict between “old” and “new” member states of the European Union.  This study seeks to investigate whether the voting pattern of the European Parliament on the issue of the Mobility Package was divided between old and new member states, or if the party groups of the European Parliament had a stronger influence. As such, the study can contribute to the research debate surrounding what role nationality and party group affiliation play in influencing the voting patterns of the European Parliament. The results of this study show that nationality seems to have had a stronger influence on the voting pattern than the party groups had. The level of cohesion was higher within member states than within party groups. Overall, the division between old and new member states seems to be a stronger predictor of voting behavior than the party groups as well. Still, within the groups of old and new member states, there are differences in voting patterns between different party groups, which means that party groups also seem to affect voting behavior. While this study cannot in itself explain the specific reasons behind the parliamentarians’ voting choices, hopefully, it can contribute to the aggregated knowledge of the political conflict lines facing European cooperation.