Cheshire & Wirral Partnership NHS v Abbott & Ors

In an equal-pay claim based on work of equal value, employees must identify a comparator pool and produce statistics capable of showing an appreciable pay difference between predominantly female and predominantly male groups. They do not have an unfettered right to choose the pool. The tribunal must ensure that it is logically coherent, valid and significant, and does not artificially bolster the claim. The pool should ordinarily include all advantaged workers who share the relevant characteristics and perform work held or assumed to be of equal value. Large numbers are not invariably required. For a bonus-or-no-bonus comparison, gender balance may suffice, including in a small workforce. A prima facie case shifts the burden to the employer under section 1(3) of the Equal Pay Act 1970.

Thirty-one domestic staff employed by a health authority claimed equal pay with porters, asserting that their work was of equal value and that they should receive the same bonus. The domestic staff were predominantly female, while the porters were male and predominantly received the bonus. The Employment Tribunal held that the employer had not established a material factor defence under section 1(3) of the Equal Pay Act 1970 and accepted the porters as the comparator group. The Employment Appeal Tribunal upheld the approach to the comparator but remitted the issue of objective justification. The employer appealed to the Court of Appeal on the comparator issue, including the proposed inclusion of caterers, the geographical scope of the comparison and the size of the comparator group.

Lord Justice Keene gave the leading judgment. Sir Christopher Staughton and Lord Justice Auld agreed. The appeal was dismissed.

1. The initial burden in an indirect sex-discrimination equal-pay claim rests on the employee. The employee must identify a comparator group and produce statistical evidence showing an appreciable difference in pay between jobs of equal value. The tribunal must itself ensure that the proposed pool is valid; there is no unrestricted right to choose a comparator. This followed the approach in Nelson v Carillion Services Limited [2003] EWCA Civ 544 and Enderby v Frenchay Health Authority [1994] 1 AER 495.
2. Identification of the pool is a matter of logic within a legal framework, rather than discretion or unrestricted fact-finding. The comparison should ordinarily be between the disadvantaged and advantaged groups. All advantaged workers sharing the relevant characteristics and performing work held or assumed to be of equal value should be included. Excluding the caterers, who also received the bonus, made the use of the porters alone arbitrary and artificially strengthened the claim. The approach was consistent with Allonby v Accrington and Rossendale College [2001] EWCA Civ 529 and Barry v Midland Bank Plc [1999] ICR 859.
3. The statistical exercise must be valid and significant. The tribunal must consider whether the figures cover enough individuals, show an appreciable difference and avoid purely fortuitous or short-term phenomena. The large-number discussion in Specialarbejderforbundet I Danmark v Dansk Industri, acting for Royal Copenhagen A/S [1995] IRLR 648 was particularly concerned with piecework and average pay. It did not make a large comparator group necessary in every case.
4. For an identified difference such as the presence or absence of a bonus, the gender balance within the groups may provide a meaningful comparison. A comparator group of 37 employees was not too small, especially since it comprised the totality of the employer’s ancillary workers receiving the bonus. The comparison could properly cover all the employer’s establishments because the bonus scheme operated across them; different bonus rates did not matter where the complaint concerned the existence of the bonus itself.
5. The corrected comparator group comprised approximately 65% men, while the domestic staff were approximately 90% women and overwhelmingly lacked the bonus. That was sufficient to establish a prima facie case under Enderby. The conclusion would therefore have been the same despite the tribunal’s error, so no remittal was required on the comparator issue.

• Court of Appeal (Civil Division): dismissed the appeal. [2006] EWCA Civ 523
• Employment Appeal Tribunal: upheld the Employment Tribunal’s approach to the comparator group, but allowed the appeal to the limited extent that the reasoning on objective justification required reconsideration and remittal.
• Employment Tribunal, Liverpool: by a decision dated 18 April 2005, held that the employer had not established a material factor defence under section 1(3) of the Equal Pay Act 1970.