"The Respondent argued that a bonus scheme was not practicable because of the finite nature of building cleaning work. We found against them in respect of that. We have found also that there is no adequate evidence to find that a bonus had been refused by cleaners and that there is no evidence of comparable wages or conditions."
"…The EAT considered that, if a tribunal found that there had been disparate adverse impact (at least if the statistical evidence was convincing), it would usually be impossible in practical terms for the employer to show that the pay disparity was not related to the difference in sex. In particular, in an Enderby -type case, where the disadvantaged group comprised all or almost all women and the advantaged group were all or almost all men, it would be impossible in practical terms for the employer to show that the pay differential was not related to the difference of sex. Thus, although in theory, it was right to say that an employer could still show that the pay differential was not due to the difference of sex, even in the face of disparate adverse impact, it would only be possible in a case where the statistical evidence was not very strong or convincing. We are inclined to think that that analysis of the decision [of the Court of Appeal in Armstrong ] is correct."
"… The burden passes to the employer to show that the explanation for the variation is not tainted with sex. In order to discharge this burden the employer must satisfy the tribunal on several matters. First, that the proffered explanation, or reason, is genuine, and not a sham or pretence. Second, that the less favourable treatment is due to this reason. The factor relied upon must be the cause of the disparity. In this regard, and in this sense, the factor must be a 'material' factor, that is, a significant and relevant factor. Third, that the reason is not 'the difference of sex'. This phrase is apt to embrace any form of sex discrimination, whether direct or indirect. Fourth, that the factor relied upon is or, in a case within s.1(2)(c) [not the present case] may be a 'material' difference, that is, a significant and relevant difference, between the woman's case and the man's case."