In Bilka-Kaufhaus GmbH v Weber von Hartz [1986] IRLR 317 ECJ, the European Court of Justice held that the exclusion of part-time workers from occupational pension schemes contravenes Article 119 of the Treaty of Rome if this exclusion affects significantly more women than men, unless the employer can show that the exclusion is based on objectively justified factors unrelated to any discrimination on grounds of sex.