In this long running equal value litigation, Tesco served particulars of its material factor defence (MFD) on 7 June 2024, relying on 9 material factors. In November 2024 Tesco made an application pursuant to Rule 30 ET Rules 2013 (now Rule 31 ET Rules 2024) for permission to rely on expert evidence in a letter sent by its solicitors, in respect of 2 of the MFDs. Tesco stated that the expert evidence concerned “economics”. The ET concluded that expert evidence was not reasonably required to resolve the proceedings. Given rule 10(1) of the Employment Tribunals (Equal Value) Rules of Procedure 2013, the ET was therefore precluded from granting the Respondent’s application to adduce it. Tesco appealed.

The EAT allowed the appeal. Whilst the ET directed itself correctly by reference to CPR Part 35 and Rule 10(1) Equal Value Rules specifically noting the requirement on the ET to “restrict expert evidence to that which it considers is reasonably required to resolve the proceedings”, the ET had fundamentally misunderstood the case that was put because the EJ thought that Tesco relied on the consequences that would result from a judgment against it - in the judgment he repeatedly referred to matters such as “what a judgment in favour of claimants would mean for the cost of living”. The case was remitted to the same EJ to focus on the correct test.