EU Solidarity, Illustrated by the Covid-19 Crisis: What does EU solidarity mean in the context of free movement of goods and persons and how is this illustrated by the response to the Covid-19 pandemic?

Solidarity between the Member States of the EU is mostly called upon during times of crisis, as also now during the Covid-19 pandemic. In this article, the definition and importance of solidarity is studied with a focus on the internal market. It appears that solidarity does not have one unequivocal meaning, but that its importance and value depend per EU policy area. Yet, it is noteworthy that elements of reciprocity and altruism lie at the core of the value. In the context of the internal market, the principle is not referred to in the specific Treaty provisions on the fundamental freedoms. However, solidarity and the idea behind it can be enforced through the principle of loyalty within the meaning of Article 4(3) TEU. The reaction of the Union and the Member States to the Covid-19 outbreak illustrates how solidarity is reflected during crises. Studying the recent actions seems to confirm the conclusion that solidarity within the single market is rather a political aspiration, that is not legally binding or enforceable by itself. However, one could argue that this requires change, since it follows from the current pandemic that solidarity is crucial for the resilience of the internal market in times of crisis. The principle of loyalty can indeed play an instrumental role here and can be used to enforce the objectives of solidarity.