Court of Justice 9 October 1997, C-253/96, C-254/96, C-255/96, C-256/96, C-257/96 and C-258/96 (Helmut Kampelmann and Others v Landschaftsverband Westfalen-Lippe (C-253/96 to C-256/96), Stadtwerke Witten GmbH v Andreas Schade (C-257/96) and Klaus Haseley v Stadtwerke Altena GmbH (C-258/96).)

OPINION OF ADVOCATE GENERAL TESAURO delivered on 9 October 1997 ( *1 ) 1. The six references for preliminary rulings from the Landesarbeitsgericht Hamm in six cases pending before it, each containing five substantially identical questions, offer the Court an opportunity to interpret for the first time Council Directive 91/533/EEC of 14 October 1991 on an employer's obligation to inform employees