Trafford Borough Council v Cooksey & Ors (GMB Claimants)

In an equal-pay claim, an employer may in principle rebut a statistical presumption of sex discrimination by proving that the pay disparity has no sex taint. Where the tribunal finds that explanation unproved on the evidence, the genuine material factor defence fails.

Indirect discrimination may arise either from a provision, criterion or practice producing disparate impact, or from significant pay statistics. These are not mutually exclusive legal categories and require a common, substance-based approach. Objective justification must address the employer’s actual legitimate aim. A purported alternative which would achieve a different aim cannot show that the chosen means was unnecessary.

The appropriate comparison pool and the significance of statistics are ordinarily questions of fact and degree, bounded by logic.

Female manual workers brought multiple equal-pay claims against Trafford Borough Council. Their male comparators received bonuses, attendance allowances, on-call allowances and gritting allowances. The Employment Tribunal rejected the Council’s genuine material factor defence for bonuses, attendance allowances and on-call allowances, but accepted it for gritting allowances. It also rejected Mrs Cooksey’s claim as a caretaker because it found no disparate adverse impact.

The Council appealed the findings on bonuses, attendance allowances and on-call allowances. Mrs Cooksey appealed the treatment of the comparison pool and statistical evidence relevant to caretakers. The central issues were whether the Council had disproved sex taint, whether the on-call payment was objectively justified, and how disparate impact should be assessed in an Enderby or Bilka case.

1. The Council’s appeal was allowed in part. The appeal against the findings on bonus and attendance allowance was dismissed. The Tribunal had treated the Armstrong no-sex-taint defence as potentially available, but was entitled on the evidence to find that the Council had not shown that job susceptibility to a productivity bonus was the full explanation for the disparity. Its findings were not perverse.
2. The Tribunal was also correct that a case in which the employer applies a provision, criterion or practice with a disparate adverse impact is a Bilka case requiring objective justification. In such a case, although an Armstrong defence is theoretically available, it will be logically and practically unavailable where the employer’s own criterion created the disparate impact. This was an alternative basis only; it was not the Tribunal’s primary reasoning.
3. The on-call appeal succeeded. The Tribunal misidentified the objective-justification inquiry. It accepted that the legitimate aim was to secure skilled employees’ availability for statutory standby duties, but then considered an arrangement under which employees would be on call without extra payment. That was a different aim. On the findings, payment was the only practicable means of securing the required availability. The EAT substituted a finding that the genuine material factor defence succeeded for on-call allowances.
4. Mrs Cooksey’s appeal succeeded in part. The Tribunal wrongly treated the Enderby and Bilka approaches as mutually exclusive and failed to apply the common approach in Bailey. The selection of a comparison pool and assessment of statistical significance are fact-sensitive. The Tribunal had not properly explained why caretakers alone formed the disadvantaged pool, nor addressed whether a significant minority of women could establish prima facie disparate impact. Those issues were remitted to the same Tribunal.

• Employment Appeal Tribunal: Allowed Trafford Borough Council’s appeal on on-call allowances and substituted a successful genuine material factor defence. Allowed Mrs Cooksey’s appeal on the caretaker comparison-pool and statistical issues, remitting them to the same Employment Tribunal. Dismissed the Council’s appeal on bonuses and attendance allowances.
• Employment Tribunal, Manchester: Judgment entered and sent to the parties on 17 February 2011. It rejected the Council’s genuine material factor defence for bonus, attendance and on-call allowances, save for Mrs Cooksey’s caretaker claim, and accepted the defence for gritting allowances.