This thesis focuses on ‘EU critical’ social movement activity in Ireland through the lens of one social movement group against the backdrop of three referenda on European treaties over a four year period. I illustrate how grievances are produced and focus on the underlying factors which motivate individuals to engage in collective action against the European Union and its reform treaties. In addressing this issue, I provide an ethnographic account of a group of Irish activists called the ‘People’s Movement’ who campaigned against the introduction of the Treaty of Lisbon in Ireland and who subsequently challenged the European Fiscal Treaty. I examine how the People’s Movement organisation collectively engage with the EU, the State, civil society and other social movement actors in their struggle for recognition and to communicate the organisation’s message. My ethnographic research is undertaken with reference to broader contextual issues, such as modern social movements, globalisation, Europe, meaning and discourse. I illustrate how the main contentious issues being debated by Irish social activists on the streets of Dublin against EU reform resonate with global social activists. I contend that Irish left-wing social activism, as a micro-movement, forms part of a greater collective and a globally networked movement of modern protest against the discontents of global capitalism. Social activist struggles in Ireland against the introduction of the EU reform treaties, while local and national in its form, can be transnational and paradoxically ‘European’ in its nature. In examining where local forms of Irish ‘activism’ are situated within modern social movement theory, I debate whether local Irish activism against the EU is post materialist in its nature, forming part of what Alberto Melucci termed as ‘new social movements’, or whether such activism against the EU is grounded in traditional class and labour struggles. I also address the historicity of such activism and reveal how such struggles form part of a fluid and continuous ‘movement’ of the Irish Left.