Final line call from the Court of Appeal on the first UK opt-out competition class action to reach trial  

06/08/25

On 1 August 2025, the Court of Appeal (Green LJ, with whom Newey LJ agreed) rejected an application by Justin Le Patourel (the Class Representative) for permission to appeal against the decision of the Competition Appeal Tribunal, of 19 December 2024, dismissing the Class Representative’s opt-out collective action against BT. The Class Representative had claimed in excess of £1 billion against BT, alleging that BT had charged excessive prices for various telephony services in abuse of its dominant position and in breach of the Chapter II Prohibition.

In its judgment of 19 December 2024 ([2024] CAT 76, the Judgment), the CAT found BT to be dominant, on a narrow product market for standalone fixed voice services, and found BT’s prices to exceed a competitive ‘cost plus’ benchmark. However, the CAT found the differential between BT’s prices and the ‘cost plus’ benchmark to be justified; hence, the prices were fair and there was no abuse of dominance.

The Class Representative, having been refused permission to appeal by the CAT, sought permission from the Court of Appeal. He advanced four grounds of appeal, two of which concerned the CAT’s assessment of Limb 1 of the test for excessive pricing under United Brands (ie, the comparison of prices and costs), one of which concerned the CAT’s assessment of Limb 2 (ie, the question of fairness of prices) and one of which concerned compound interest.

The Court of Appeal, following an oral hearing on 16 July 2025, refused permission in relation to all four grounds:

Ground 1 – by which the Class Representative alleged that the CAT erred in its approach to BT’s expert evidence on the allocation of BT’s indirect costs and should have drawn adverse inferences against BT – was, in substance, “a challenge to the factual and evaluative assessment of the CAT”.

Ground 2 – a complaint about how the CAT computed its own ‘cost plus’ benchmark – reflected a wrong assumption that the CAT had endorsed BT’s expert economist’s ‘SAC Combi’ approach. In fact, the CAT had arrived at its own conclusion, through “classic, informed, guesstimation or wielding of the broad axe”.

Ground 3 – comprising several separate complaints about aspects of the CAT’s conclusions on the fairness of BT’s prices – was “not borne out by a due reading of the Judgment” and amounted, in essence, to challenges to the CAT’s fact finding. The Court of Appeal emphasised the high threshold for turning a complaint about “the evaluative Limb 2 exercise performed by the CAT as to the weight to be given to different strands of evidence relevant to value and justification” into an appealable error of law.

In the circumstances, ground 4, concerning compound interest, was academic.

The judgment of the Court of Appeal ([2025] EWCA Civ 1061) can be read here. The CAT’s Judgment can be read here.