Bulletin of Comparative Labour Relations Volume 108 The progressive expansion of the phenomenon of posting of workers – the practice whereby a worker is sent for a limited period of time to another Member State in order to provide a service – is a formidable bone of contention in the conflict between a fully integrated internal market economy and Member States’ aims to protect domestic social standards. This book challenges the recently adopted Directive (EU) 957/2018, which came into effect in July 2020, by examining the relevant EU regulatory framework and investigating the actual quantitative dimension of the posting phenomenon and its real impact on the EU labour market. In the process, the author exposes a serious misalignment of the legal framework provided for by the new Directive with the EU values and principles of equality, solidarity and fair competition. Drawing on a wide variety of sources – including Court of Justice case law, Advocate Generals’ opinions, Eurostat data, Commission documents and reports, and academic literature – the author provides in-depth analyses of such elements of the problem as the following: proper definition of the concepts of ‘posting’ and ‘posted worker’ in EU law; host country’s discretion in relation to the part of domestic regulation it can impose on posted employees; misconceived clash between social rights and economic freedoms; coordination of national social security systems; proliferation of unlawful and fraudulent practices; ‘regime shopping’ and exploitation of existing regulatory loopholes; misleading association of posting with issues of ‘social dumping’ and ‘unfair competition’; orientation of political influence during the drafting process of relevant EU legislation; expected controversial economic impact of Directive (EU) 957/2018; concrete realisation of the EU values and principles of equality, solidarity and fair competition; and definition and pursuit of a ‘European social model’. Normative arguments developed in the course of the analysis put forward viable recommendations for future improvements in the field. The Union’s commitment to the development of a ‘European social model’ cannot avoid taking into account the matters of equality, solidarity and fair competition. In this sense, given the increasing prominence of the free movement of services in shaping a European labour market characterised by an ever-growing degree of mobility, this book’s analysis of the phenomenon of posting of workers may serve as a litmus test of political and legislative action at EU level. In its dual analytic and normative aspect, the book takes a giant step towards future discussions and developments in the area of intra-EU labour mobility. It will be welcomed by legal practitioners in labour and social security law and industrial relations, legal scholars, EU institutions and agencies, businesses and trade unions.