Member States shall adopt the laws, regulations and administrative provisions necessary to comply with this Directive by 19 July 2003 or may entrust management and labour, at their joint request, with the implementation of this Directive as regards provisions falling within the scope of collective agreements. In such cases, Member States shall ensure that by 19 July 2003, management and labour introduce the necessary measures by agreement, Member States being required to take any necessary measures to enable them at any time to be in a position to guarantee the results imposed by this Directive. They shall forthwith inform the Commission thereof.

When Member States adopt these measures, they shall contain a reference to this Directive or be accompanied by such a reference on the occasion of their official publication. The methods of making such a reference shall be laid down by the Member States.