This article studies references to ‘solidarity’ in international political debate in the context of the European Union. Our case in focus is a floor debate in the European Parliament (EUP) concerning a white paper released by the European Commission on the future of the EU in March 2017. The paper was draft in response to the shattering Brexit referendum in Britain in June 2016. In our data, the President of the Commission is visiting the EUP and introducing the paper to the Members of European Parliament (MEPs) on the day of its publication, to have it discussed and debated there first hand amongst the MEPs. Multiple arguments in the debate make sense of the situation in the frame of a ‘crisis in solidarity’. This is, however, all but one way to deploy the concept in argumentation. Political actors make use of the principle and the metaphorical associations it carries for different political purposes. In this article we explicate the strategic use of the word solidarity in a conflictual political debate. The valence of the word seems to be self-evidently positive and worth supporting for amongst all the discussants, which evidences the persuasive applicability and strength of the concept as a rhetorical tool. Yet, on the level of discursive formulations, solidarity is also very flexible. It can be signified and, indeed, populated very differently by different actors. Our research demonstrates that cultural values or imageries, even when they are widely appreciated, do not convey readymade scripts to guide social change. Rather they serve as resources local actors mobilize to motivate their political claims. Our research takes part in the discussion on the strategic entanglement of ideas, beliefs and interests in governance talk. We highlight the usability of identifications, positionings and normative expectations in political discourse, approaching political justifications from the perspective of discursive institutionalism, epistemic governance and membership categorization analysis.