This chapter examines the recent controversial decisions of the ECJ in Viking and Laval, focusing on how they are likely to be applied in practice. Firstly, it considers the rules regarding the applicable forum and the procedures for going to court in the UK, then it looks at when it can be said that an employer’s economic rights under EU law have been engaged and when there has been a ‘restriction’ on those rights. It goes on to address the core issue of the circumstances in which a ‘restriction’ on the relevant EU economic right pursues a ‘legitimate aim’ and then considers the key battleground in future cases falling under Viking and Laval, namely whether the industrial action is ‘proportionate’. Finally, it addresses an important, but unresolved, issue: the extent to which industrial action in breach of Articles 43 or 49 EC could give rise to liability in damages.