Welcome to the jungle: The Competition Appeal Tribunal rejects Amazon's strike-out of a new claim but imposes firm case management directions

Precis

A strike-out application by Amazon against a CPO brought by the Association of Consumer Support Organisations (ACSO) for damages to consumers relating to "price parity policies" on the Amazon UK marketplace, in view of the apparent overlap between this claim and two claims already certified concerning similar subject matter.  The strike out was rejected by the Competition Appeal Tribunal.  However, the Tribunal has proposed firm case management proposals including for joint instruction of single experts alongside a pre-existing consumer collective action claim.  

Introduction

On 14 August 2025, ACSO filed an opt-out collective proceeding's application with the Competition Appeal Tribunal (CAT) alleging an abuse of dominant position and / or anti-competitive agreements between Amazon and merchants on the Amazon UK marketplace.  For the purposes of the strike-out application ACSO's allegations regarding Amazon's "price parity policies" were most relevant to the Tribunal's assessment and accordingly will be the focus of this article.  These policies are alleged to apply to merchants selling on the Amazon UK marketplace and "prevent or strongly discourage" merchants from offering lower prices for their products than on other e-commerce platforms.  This, according to ACSO, lead to higher fees for merchants which were then passed on to consumers.

ACSO was established in 2019 to represent the interests of consumers in the civil justice system, this is their first time spearheading a collective action, and it has commented that it sees this as an "important way  for consumers to gain access to justice and or examples of poor corporate behaviour to be challenged".

ACSO's claim was filed several years after claims were initially brought by Robert Hammond in June 2023 (acting on behalf of consumers who purchased from Amazon's UK marketplace) and Prof. Andreas Stephan in June 2024 (acting on behalf of the Amazon UK merchant class).  Mr Hammond and Prof. Stephan's claims were both certified as opt-out claims at a joint certification hearing in May 2025. The claims are jointly case managed to ensure efficiency and reflect the overlapping factual and technical issues.  ACSO's claim is, as yet, uncertified. 

ACSO's claim is on substantially the same grounds to Mr Hammond's albeit Mr Hammond does not advance allegations regarding "price parity policies" which ACSO does.  Instead, Prof. Stephan's claim makes the same argument about Amazon's alleged anti-discounting practices affecting the merchant class. There is also a difference in the temporal scope due to ACSO filing its claim two years after Mr Hammond and reserving the right to extend the claim period beyond August 2025, therefore possibly benefiting an otherwise unrepresented group of consumers.

In light of the overlapping allegations made by Prof. Stephan, Mr Hammond and ACSO, Amazon sought to strike-out ACSO's claim.

Facts

In January 2026, Amazon applied for strike-out of the ACSO claim.  This was on the basis that it was an abuse of process pursuant to the Tribunal's inherent power to, as described in the ruling, "prevent misuse of its procedure which would be manifestly unfair to a party to litigation or otherwise bring the administration of justice into disrepute".

Amazon argued that:

1. The situation was not amenable to consolidation or joint case management.

   The consumer class already had a representative in the form of Mr Hammond whose CPO was made in November 2025.  The "price parity" allegations could have been raised by Mr Hammond, but he had chosen not to do so.  On that basis it would therefore be wrong to allow a separate, independent representative to advance these claims.  Should ACSO's claim be allowed to proceed it would lead to, in effect, two consumer class representatives with consequent difficulties in dividing the spoils should they be successful as arguments would erupt regarding the causative attribution of the damages.

2. Additional burden

Amazon argued that the burden of fighting a further claim would be unreasonable.  They referred to the war chest of £20 million in budgeted spending to trial which ACSO had amassed.  This, Amazon argued, was entirely disproportionate in circumstances where Mr Hammond could have advanced the "price parity" claim alongside his pre-existing points for a fraction of this cost.

There was also concern about the wider impact of allowing ACSO's claim to proceed and a risk of others coming forward with similar claims addressing particular lacunae in pre-existing cases and duplicating work.  Amazon made strident arguments that ACSO's claim would be seen in the eyes of the public to be merely a vehicle for funders, lawyers and economists to enrich themselves.  These wasteful proceedings would bring the regime itself into disrepute and would not be fair on Amazon nor, due to the increased administrative burden, on other users of the Tribunal. See transcript page 24, lines 10 - 13 for more information. 

Decision

The Tribunal noted that Amazon had not sought to argue that ACSO's "price party policy" argument was unfounded or that it did not raise an arguable case. The CAT recognised that ACSO's claim offered an opportunity for consumers to obtain redress should the following occur:

1. Prof. Stephan successfully shows that Amazon had adopted anti-discounting practices for merchants, leading to increased costs; and

2. At least some of those increased costs incurred by merchants was passed-on to consumers.

If the claims were struck-out this would be a windfall for Amazon and an unrecovered loss for the consumers.  Adopting the language of the test for strike-out, the Tribunal found that it would "bring the administration of justice into disrepute" not to proceed with the ACSO claim in circumstances where a proposed class representative was ready to and had the necessary financial support to prosecute proceedings.

It is reasonable to ask why Mr Hammond did not simply amend his claim form to reflect the "price party" argument. However, for whatever reason, Mr Hammond had not done so and it would be wrong to subordinate decision making in the claim to Mr Hammond alone when an alternative was ready to fight for these distinct consumer class members.

Accordingly, it was not unreasonable for ACSO to pursue this claim.  Notwithstanding this, the Tribunal acknowledged that proceedings should not become oppressive to defendants.  To address this tight case management was required with the trying common issues together.  Between ACSO and Mr Hammond there was an expectation that a single expert would be instructed where interests aligned. Cooperation between the sets of lawyers, to reduce any duplicative correspondence to Amazon and therefore expenditure, was also proposed.

The Tribunal also rejected the risk of "a hypothetical spectre of a dispute in due course over the attribution of damages, as a basis for striking out.  While not a reasonable basis for preventing ACSO's claim, it will be interesting to note in due course how (should they be successful) any damages are attributed to the claims advanced by the two consumer class representatives. 

Comment

It is noteworthy that the Tribunal, mirroring language from the Evans v Barclays Bank Plc and Others[1] Supreme Court ruling, acknowledged that class action proceedings should not be used oppressively against defendants.  However, the Tribunal considers it has addressed this risk by proposing stringent case management requirements. For ACSO the consequences could be significant.  Should their claim be certified, they are likely to be tied to expert(s) who they did not choose and align their position and correspondence closely with Mr Hammond.  ACSO will, however, have the benefit of obtaining any concessions or disclosure already obtained from Amazon and pioneered by Mr Hammond.  This is likely to be a significant time and cost saving.

Inherent in this case is a warning to both class representatives and defendants that a group could spy an opportunity to advance an un-pleaded argument or exploit a sliver of unaccounted time to advance a claim.  On the one hand, this may be beneficial for class representatives where extra firepower means a more equal balance of resources between the parties and for defendants, certainty about the legality of all aspects of the relevant businesses' models under review.  However, on the other hand, it opens the gate for increased costs for all parties, enforced cooperation for class representatives and no increased litigation risks on defendants.     

Case number: 1749/7/7/25 Association of Consumer Support Organisations Ltd v (1) Amazon.com, Inc., (2) Amazon Europe Core S.À.R.L., (3) Amazon EU S.À.R.L, (4) Amazon U.K. Services Ltd., and (5) Amazon Payments U.K. Limited