This paper argues that the justification defence in UK statutory indirect discrimination cases should incorporate proportionality as applied by the European Court of Human Rights (ECtHR). It first analyses the evolution of the UK approach to proportionality before the enactment of the Human Rights Act 1998 (HRA), when its primary influence was the jurisprudence of the European Court of Justice (ECJ) applying EC equal treatment directives. This assessment shows that the UK judiciary was already adopting an approach to proportionality at odds with that of the ECJ and more resonant with that of the ECtHR. An evaluation of UK practice, however, including consideration of GMB v Allen, shows that UK judges do not apply the rigorous scrutiny required by either the ECJ or ECtHR approaches. The article considers the doctrine of proportionality as developed through the discrimination jurisprudence of the ECtHR and its application under the HRA. Given the increasing relevance of European Convention on Human Rights precedent under the HRA, the article evaluates how the influence of Strasbourg teaching can (and should) enhance the UK approach to the resolution of employment discrimination claims.