18After noting the case-law concerning the principles governing the possibility of relying on Community directives (Case 57/65Lütticke [1966] ECR 205; Case 41/74Van Duyn [1974] ECR 1337; and Case 103/88Fratelli Costanzo [1989] ECR 1839), the Commission submits that where a tax provision gives rise to direct effects, not only tax creditors and taxpayers must be able to rely upon it, but also, outside the binary relationship between the latter and the tax authorities, third parties affected by the application of such a provision.