In a case involving part-time cabin crew at British Airways, the Court of Appeal has delivered some important guidance on a key aspect of the genuine material factor (GMF) defence. In Grundy v British Airways plc the Court of Appeal confirmed that the employment tribunal (ET) had chosen the correct pool to determine whether the employer's pay structure indirectly discriminated against women.

The dispute arose because, unlike their full-time counterparts, support cabin crew (an exclusively part-time grade to which the claimant belonged) were not entitled to annual increments. The numbers of support cabin crew were small compared to the numbers of full-time staff, but they had a much higher ratio of women, so it was important to the claimant that the "disadvantaged" group was chosen as the pool. Otherwise the potentially adverse impact of the pay structure on women would be diluted by the much larger number of women who were employed full-time, and who did enjoy annual increments.

The Court of Appeal decided that there was no overall principle which determined the selection of the pool in equal pay cases. The key point was that the ET should find a pool in which "the specificity of the allegation can be realistically tested". So in this case the ET's decision to concentrate on the support cabin crew (ie, the disadvantaged group) could not be faulted. This is not the end of the litigation, however, because the employer's appeal on the justification issue is still to be heard.

Click here for the full decision.