Trafford Borough Council v Cooksey & Ors (GMB Claimants)

Where an equal-pay claimant establishes disparate adverse impact, an employer may in principle show that the pay difference has no sex taint. That defence is difficult where convincing statistics reveal long-standing gender segregation, and it failed on the facts concerning bonus and attendance allowances.

Where the employer itself applies a provision, criterion or practice which causes the disparate impact, the issue is objective justification. The employer must identify the actual legitimate aim and show that the means used are appropriate and necessary. An alleged alternative which pursues a different aim cannot defeat justification.

The distinction between statistical and provision, criterion or practice routes to indirect discrimination does not require mutually exclusive approaches to comparison pools. Pool selection and statistical significance are fact-sensitive exercises bounded by logic.

Female manual workers brought multiple equal-pay claims against a local authority. They compared themselves with male manual workers and challenged bonus, attendance, on-call and gritting payments. At a pre-hearing review, the Employment Tribunal rejected the employer's genuine material factor defence for bonus, attendance and on-call allowances, but accepted it for gritting allowances.

The authority appealed the adverse rulings on bonus, attendance and on-call payments. A caretaker, Mrs Cooksey, appealed the rejection of her claim because the Tribunal found no prima facie disparate adverse impact on women in the caretaker group.

The central issues were the scope of the no-sex-taint defence under Equal Pay Act 1970, objective justification for an on-call allowance, and the proper approach to comparison pools and statistics in establishing indirect sex discrimination.

1. The authority's appeal on bonus and attendance allowances was dismissed. The Employment Tribunal's primary reasoning was that the authority had failed to prove that its explanation for the pay arrangements was free from sex taint. It had treated the no-sex-taint defence as potentially available, rather than excluding it. Its findings that the historic bonus arrangements had not been comprehensively considered for female-dominated work, and reflected the pattern of full-time male employment, were open to it on the evidence.

2. The Tribunal had not erred by treating the approach in Cumbria County Council v Dow (No 1) and Coventry City Council v Nicholls as an alternative basis. Where an employer itself applies a criterion which produces disparate adverse impact, the criterion is indirectly discriminatory unless objectively justified. In that situation, the employer cannot in practice show that the impact has nothing to do with sex. This conclusion was not necessary to dismiss the appeal because the Tribunal's primary findings already disposed of it.

3. The authority's appeal on the on-call allowance was allowed. The Tribunal had correctly found a genuine and material reason and a legitimate aim: securing skilled employees' availability for statutory stand-by duties. It then erred by treating unpaid contractual on-call work as a less discriminatory means. That alternative pursued a different aim, namely securing availability without payment. On the findings made, payment was plainly the necessary means of securing the required on-call service. The Appeal Tribunal substituted a finding that the genuine material factor defence succeeded for all claimant groups.

4. Mrs Cooksey's appeal was allowed in part and remitted. The Tribunal wrongly treated the Enderby and Bilka approaches as mutually exclusive and failed to apply the common approach required when selecting the comparison pool. It also treated the absence of a female majority among caretakers as determinative without considering whether the statistics nevertheless showed prima facie disparate impact. Pool selection and statistical significance are questions of fact and degree, bounded by logic. The case was remitted to the same Tribunal to determine the proper pool and, if necessary, the statistical issue under the correct approach.

• Employment Appeal Tribunal: The Tribunal dismissed the authority's appeal concerning bonus and attendance allowances, allowed its appeal concerning on-call allowances and substituted a finding for the authority, and allowed Mrs Cooksey's appeal in part. The caretaker issues were remitted to the same Employment Tribunal.
• Employment Tribunal, Manchester: Following a pre-hearing review, the Tribunal rejected the genuine material factor defence for bonus, attendance and on-call allowances, except for bonus and attendance in Mrs Cooksey's case. It accepted the defence for gritting allowance.