The debate on the introduction of the so-called social clause has been ongoing since a number of decades, and has particularly become lively since the 1999 WTO Ministerial Conference in Seattle. Advocates of the social clause are of the opinion that compliance with labour rights should be one of the issues dealt with by the GATT/WTO. They consider the GATT/WTO, and especially Article XX of the GATT, as being particularly well-placed, because of the capacity to impose trade sanctions on non-compliant member states. In view of the far-reaching consequences of trade sanctions, it is not surprising that the debate has given rise to a vociferous debate among legal experts. This book takes as its starting point the observation that a social clause should be concerned with achieving international labour rights. Hence, a thorough analysis of the conception of international labour rights is undertaken, involving not only law but also other disciplines such as history, morality and economics. By reconstructing an adequate conception of labour rights, an attempt is made to guide the current debate and to assess whether the social clause can be an adequate mechanism for implementing international labour law. The analysis shows that the discussion on the social clause is emblematic of the way the WTO and the international trade system should deal with human rights in general. Hence, a study of the topic also requires an approach grounded in international law in the broadest sense, covering general international law, international human rights law, international trade law, international labour law and legal theory. The book aims in the first place to be an eye-opener for jurists dealing with this issue. However, because of its interdisciplinary approach, it may also appeal to policy-makers and other readers interested in an in-depth study of the subject.