It held that the EU: is not merely an economic union, but is at the same time intended, by common action, to ensure social progress and seek the constant improvement of the living and working conditions of their people...The case was championed by the Belgian lawyer Éliane Vogel-Polsky, who was responsible for much of the heavy involvement in sex discrimination law of the time by the European Court of Justice.

[1] A woman named Gabrielle Defrenne worked as a flight attendant for the Belgian national airline Sabena.

Under Belgian law, female flight attendants were obliged to retire at the age of 40, unlike their male counterparts.

This double aim, which is at once economic and social, shows that the principle of equal pay forms part of the foundations of the Community.

The prohibition on discrimination between men and women applies not only to the action of public authorities, but also extends to all agreements which are intended to regulate paid labour collectively, as well as to contracts between individuals.This, further to the case of Van Gend en Loos, identified the horizontal and vertical direct effect of Treaty provisions which could be invoked in national courts and hence they would be bound to protect individual rights.