For decades, the posting of workers has been a prominent topic of the public and political debate.

However, in the last few years, several factors have intensified the debate. Firstly, an increase in the number of postings, which has impacted heavily in specific labourintensive sectors. Secondly, there has been a growth in abusive and fraudulent practices such as letter-box companies or bogus self-employment. Thirdly, in view of the social policy provisions introduced into the European Treaties since the Lisbon Treaty revision, it is questionable whether the 1996 Posting of Workers Directive (PWD) provides a sufficient legal instrument for ensuring a level-playing field for free cross-border service provision whilst at the same time delivering a sufficient foundation for the social protection of workers. Fourthly, numerous rulings of the Court of Justice of the European Union have raised as yet unsolved questions for interpreting the 1996 Directive.