The book reflects on constitutional balancing from the perspective of fundamental labour rights. It draws on neo-constitutional theories and builds on the assumption that fundamental labour rights, understood as rights aimed at protecting workers during their working life or after retirement, are the normative expression of founding values and can be balanced against equally axiological constitutional principles. The balancing of constitutional labour rights can be conducted by various institutional actors and by applying different techniques. This volume reviews the theoretical debates on judicial balancing and the approaches adopted by the Court of Justice of the European Union and the European Court of Human Rights, to proceed with a closer assessment of Italian and Spanish judicial traditions. In particular, it addresses the main profiles of the case law of the Italian and Spanish Constitutional Courts on labour and social law reforms adopted in the aftermath of the 2008 crisis, where balancing takes place between labour rights and economic principles. The analysis is focused on four main aspects: the fundamental labour rights in the balance; the role of the Courts; the technique applied by the Judges; and the constitutional interests subject to the balancing. It ultimately reveals that the axiological nature of fundamental labour rights is preserved and the economic and financial contingencies confirm their factual character, although they are occasionally recognised a prominent role in the ratio decidendi. The book will be a valuable resource for academics and researchers working in the areas of labour law, social security law, legal theory and constitutional law.