United Kingdom of Great Britain and Northern Ireland v. Council of the European Union, Case C-84/94, CJEU, 12 November 1996

Weekly rest of workers and prohibition of Sunday trading. Cultural, ethnic and religious diversity of the Member States. 

Council directive 93/104/EC of 23 November 1993 concerning certain aspects of the organization of working time

1. Article 5(2) of Directive 93/104/EC (no longer in force), concerning the organisation of working time shall be declared null and void. The question of whether Sunday should be included in the weekly rest period was left to the discretion of the Member States, taking account in particular of the diversity of cultural, ethnic and religious factors in the various Member States. 

2. The Council, however, failed to explain why Sunday, as a day of weekly rest, would have a more important connection with the health and safety of workers than another day of the week.