The purpose of this Study is to provide an in-depth, objective description and analysis of the law and practice of arbitration, public policy argument in commercial arbitration across the European Union. One of the primary goals of the Authors was to portray accurately the actual diversity of arbitration law and practice across the European Union, rather than merely to report on arbitration practice as it is undertaken by the leading specialists in the field, and on arbitration law in the primary arbitral jurisdictions. Consequently, it was decided to include discussion of the law and practice of arbitration of all the States of the European Union, in order to identify both similarities and variants, and in order to discuss the strengths and weaknesses of the law and practice observed, in the specific national contexts in which it is found . Public policy is one of the most popular grounds commonly used by parties to international arbitration to resist enforcement of arbitral awards. Till today, it remains a highly debated, controversial and complex subject. This is because of the diverse approach taken by national courts in relation to the concept of public policy in international arbitration. Although over time, arbitration laws and practice have tried to align the concept of public policy so that parties may benefit from a universally accepted concept of public policy, the difference in attitude of national courts has made this task virtually impossible. In recent times, the difference in attitude has been most prominent in India, where a series of court decisions have hampered the development of an internationally accepted concept of public policy.