D.A.C.6 in the E.U. requires Member States to impose a disclosure obligation on intermediaries who advise on, or are involved in, implementing aggressive cross-border arrangements. This poses a conundrum for tax lawyers involved in a transaction because, whatever they do, rights of taxpayers and duties of attorneys to maintain client confidences may be ignored, or significantly cut back. In Belgium, the approach is to ignore Belgian case law that recognizes the obligations of lawyers to keep confidences and forces attorneys to violate various obligations to clients. Not surprisingly, the Belgian Bar Councils and the Belgian Association of Tax Lawyers have challenged the restrictive interpretation of the L.P.P. before national and European courts. Werner Heyvaert, a partner at the Brussels office of AKD Benelux Lawyers, and Vicky Sheikh Mohammad, an associate at the Brussels Office of AKD Benelux Lawyers, explain the five reasons why Belgian implementation of D.A.C.6 is flawed. The case is currently under consideration by the C.J.E.U.