Council Directive 75/117/EEC

Council Directive 75/117/EEC of 10 February 1975 on the approximation of the laws of the Member States relating to the application of the principle of equal pay for men and women is composed more accurately than the Treaty of Rome. It applies the principle of the work of equal value and it makes a wider comparison possible.
The Directive announces the “The principle of equal pay for men and women hereinafter called "principle of equal pay", means, for the same work or for work to which equal value is attributed, the elimination of all discrimination on grounds of sex with regard to all aspects and conditions of remuneration.” 75/117/EECC, Article 1
This Directive is especially important because the principle of equal work in the Treaty of Rome could only be interpreted narowly, only in that case when the work was exactly the same in exactly same circumstances. The Directive, however, introduces the principle of work of equal value and it makes a broader comparison possible.
Member States shall abolish all discrimination between men and women arising from laws, regulations or administrative provisions which is contrary to the principle of equal pay.