Hello everyone and thank you for joining us for another case of the week update. For those of you that don’t know me, I’m Kyle and I’m one of the solicitors here at PJH Law. For those of you who missed our last update, you can find that here. This week, we are looking at a case involving over 50,000 Claimants.

In a significant development for large-scale and extended equal pay litigation, the Employment Appeal Tribunal (EAT) has allowed Tesco’s appeal against a decision refusing permission to introduce expert economic evidence in its ongoing equal pay battle. The case, involving over 50,000 store workers claiming their work is of equal value to distribution centre colleagues, centres on whether Tesco can justify pay differences between these roles based on market factors and business considerations.

Employment Judge Hyams had initially rejected Tesco’s application to introduce expert economic evidence on labour markets and the business consequences of higher store worker pay. The EAT ruled this was an error, finding the judge had incorrectly focused on whether such evidence was “relevant” rather than applying the proper test of whether it was “reasonably required to resolve the proceedings.” The EAT emphasised that expert evidence should be permitted if necessary to resolve an issue, or if helpful and justified when balanced against factors like cost and delay.

This decision serves as an important reminder for HR professionals that material factor defences in equal pay claims may require robust expert evidence to support commercial justifications. Organisations facing similar claims should carefully consider whether expert evidence might strengthen their position on market rates, recruitment challenges, or business sustainability factors. The case has been remitted to the same Employment Judge for reconsideration, with the substantive hearing on Tesco’s material factor defence scheduled for September 2025.

Takeaway Points

When defending equal pay claims, employers may need expert economic evidence to support ‘material factor’ defences based on market forces and business considerations – the EAT confirmed that tribunals must apply the correct test of whether such evidence is “reasonably required to resolve the proceedings” rather than simply dismissing it as irrelevant.

While the case is quite lengthy and technical, the key element of this decision was regarding the use of expert witnesses. It is worth bearing in mind the ‘value’ of the work performed in comparing work between male and female majority areas of the workplace.