Part II: Freedom of Movement Under Attack: Is it Worth Defending as the Core of EU Citizenship? Abstract This forum debate discusses the link between Union citizenship and free movement. These concepts were long understood as progressive and fundamental mechanisms in drawing the citizen closer to the European integration project. Both concepts now appear in crisis. This is, of course, reflected in the run-up to, and outcome of the Brexit vote. But criticism on the link between Union citizenship and free movement must be understood in a wider context. It is the context within which welfare systems are perceived to struggle with the incorporation of migrant citizens; and within which the benefits linked to free movement are perceived to fall to specific groups or classes of citizens in society. This forum debate takes on this discussion in two different ways. One the one hand, it discusses whether free movement contributes to, or detracts from, the capacity of the EU to create a more just or legitimate relationship between its citizens. On the other hand, it discusses whether Union citizenship – a status that is fundamental to all nationals of the Member States, whether they move across borders or not – should be centred on free movement, or whether we need to rethink the premise of what it means to be a European citizen. Keywords Free movement; EU citizenship; Migration; Mobility; Brexit; Welfare.