This case considers the temporal scope of a pay comparison in proceedings based on equal pay for work of equal value brought under the Equal Pay Act 1970.

The claimants sought arrears of pay dating back to 2002, arguing the work they completed was of equal value to C, a male employee who worked as a highways operative. However, circumstances changed in April 2006. One of the comparators, C, was promoted and the other, P, was assimilated onto a Single Status Scheme at a lower rate of pay. The Council challenged the duration for which the arrears were sought and argued the claimants could not compare themselves with C and P for the purposes of calculating their arrears claims.

The tribunal rejected this argument stating the claimants were entitled to arrears of pay and that this should be assessed on the higher rate of pay following C’s promotion and the unreduced salary of P.

The Council appealed the decision to the EAT. It maintained that where an individual in the comparator role is in post during the whole period of comparison then the sex equality clause operates with respect to that individual; however it argued that the position is different if he leaves during the comparison period, and stated different valid comparators continued in post while the chosen comparator did not.

Dismissing the appeal, the EAT held the fact that there were other comparators available did not and could undermine the claimants’ entitlement to equal pay. Once the claimants’ pay was elevated by application of the sex equality clause it remained at that level irrespective of what happened to the comparator's pay. The EAT ruled there is no temporal limitation and the accrued contractual right continues until it is validly varied or terminated.

“Nothing has been shown to have happened to terminate, modify or vary the claimants' contracts. Their crystallised rights continue notwithstanding that C was promoted in 2006. I can see no ground for denying them compensation on this basis... the same principle applies in the case of P. Although his contract was varied when he was placed on the Single Status Scheme, the claimants did not agree to a variation of their pay and they were not assimilated onto Single Status terms. Since their contracts were not validly varied, their crystallised rights also continued”.
http://www.bailii.org/uk/cases/UKEAT/2018/0222_17_0706.html

In Northern Ireland the Equal Pay Act (NI) 1970 requires employers to pay men and women equal pay for equal work. It prohibits sex discrimination between employees in respect of their contractual pay and terms and conditions of employment. A woman doing equal work with a man in the same employment is entitled to equality in pay and other contractual terms, unless the employer can show that there is a genuine material reason for the difference which does not discriminate on the basis of her sex. Where there is equal work, the law implies a sex equality clause automatically into the woman's contract of employment, modifying it where necessary to ensure her pay and all other contractual terms are no less favourable than the man's. If the employer is unable to show that the difference is due to a genuine material factor which has nothing to do with her sex, then the equality clause takes effect.