Spottiswoode proceedings: UK Competition Appeal Tribunal decides that power cables infringement had no effect on electricity bills via UK renewables subsidies

In May and June 2025 the UK Competition Appeal Tribunal (‘CAT’) held a preliminary issue trial, in the context of wider collective proceedings, to determine whether electricity consumers in Great Britain could have paid higher prices due to an alleged overcharge on power cables. Compass Lexecon was engaged by power cable manufacturer Prysmian to provide expert testimony on the potential effects of a hypothetical overcharge on the UK government’s subsidy levels for offshore wind farms. Our assessment was that the alleged overcharge in the price of power cables was most likely not sufficiently material to have affected the level of subsidy. In its October 2025 judgment the CAT came to the same conclusion, determining that subsidies for offshore wind farms set by the UK government would have been the same in the absence of the alleged overcharge, and hence that the class of electricity consumers suffered no loss via the subsidy scheme. It noted that the Compass Lexecon expert witness Dr Boaz Moselle gave “clear and cogent evidence”.

Situation

In April 2014, the European Commission found that several power cable manufacturers had infringed Article 101 TFEU as a result of an anti-competitive infringement between 1999 and 2009 (case AT.39610). The current collective proceedings (“the Spottiswoode proceedings”) are a follow-on damages claim brought on behalf of UK electricity consumers. The class representative allegedinter alia that the UK government set higher subsidies for offshore wind farms than it would have set in the absence of the infringement, because the infringement raised the cost of cables used by offshore wind farms. She claimed that the cost of the subsidies was ultimately passed on to electricity consumers in the UK (“the class”).

Our role

The preliminary issue trial addressed one part of Spottiswoode’s case: the question of whether in 2010 the UK government would have set lower subsidies for offshore wind. Compass Lexecon assisted Macfarlanes, counsel to Prysmian Cavi E Sistemi S.r.l. and Prysmian S.p.A (‘Prysmian’) by assessing:

• the impact that the alleged overcharge from the power cables infringement could have had on the costs of those offshore wind farms whose costs informed the UK government’s subsidy decision; and
• whether the impact of the alleged overcharge would have resulted in a lower level of subsidies in the absence of the infringement.

Our assessment was that the alleged overcharge was most likely not sufficiently material to have resulted in a lower level of subsidies in the absence of the alleged overcharge. Dr Boaz Moselle gave oral testimony on the preliminary issue trial at the CAT.

Outcome

On 30 October 2025 the CAT issued a judgment following the preliminary issue trial. The CAT concluded that the level of the offshore wind farm subsidy would have been the same in the absence of the alleged overcharge. Therefore, any impact that the infringement may have had on the price of cables used by offshore wind farms could not have been passed on to the class through the subsidy scheme. The CAT found that Dr Moselle gave “clear and cogent evidence”.

The team

Dr Moselle was supported by a team of economists including Despina Doneva, Juan Carlos Bisso, Finlay Yates, and Tian Jiacheng. Compass Lexecon worked with a Macfarlanes team that included Simon Day, Cameron Firth, Rachel Carter; and with barristers Helen Davies KC from Brick Court Chambers and Fiona Banks from Monckton Chambers.