The case started when plaintiffs relied on Equal Treatment Directive in a claim of unlawful sexual discrimination. Though the directive was found to be too imprecise to give direct effect, the court said that to ensure compliance with EC directives, national courts should interpret domestic legislation within the directive’s confine. Thus, although P cannot sue D under a directive, they can sue D under national legislation and demand that the national legislation be interpreted in the light on the directive.
However the courts said that the duty to implement legislation in the light of directives was limited by the principles of legal certainty and non-retroactivity: unclear how this will be applied.