Competition | UK Regulatory Outlook September 2026

European Commission adopts guidelines on exclusionary abuses

On 3 September 2026, the European Commission adopted guidelines on exclusionary abuses of a dominant position. Following publication of these guidelines, the Commission has withdrawn its 2008 guidance on enforcement priorities in relation to abusive exclusionary conduct by dominant undertakings. The new guidelines will come into force in early October.

The guidelines set out the legal and economic framework the Commission uses to assess exclusionary conduct with the aim of enhancing legal certainty in this area and helping companies to self-assess their business practices. They outline that, in order to prove an exclusionary abuse of dominance, it must be demonstrated that conduct by a dominant firm distorts effective competition by departing from competition on the merits and produces, at least potentially, exclusionary effects. However, they explain that there are situations where it is not necessary to separately demonstrate that these two criteria are fulfilled. These situations arise when the dominant firm's conduct either fulfils the requirements established by the EU courts, is capable of excluding a hypothetical equally efficient competitor, or is by its very nature (that is, by object) harmful to competition. It will be interesting to see how the Commission interprets this by-object requirement as distinct from capability to foreclose equally efficient rivals and from likelihood to produce exclusionary effects. It is notable that the guidance has moved away from the use of a significant number of presumptions of likely competitive harm as a result of feedback.

This detailed treatment of specific forms of exclusionary conduct codifies several judgments of the EU courts and is one of the most useful aspects of the guidelines. The types of conduct considered include: predatory pricing, margin squeeze, conditional rebates, exclusive dealing, tying and bundling, access restrictions, refusal to supply and, reflecting the most recent case law in digital markets, self-preferencing.

Alongside this, the guidelines provide substantial exploration of the business justifications defence. This is one of the most welcome developments in the final guidelines. The defence may allow the conduct to escape the prohibition against abuse of dominance. It applies to conduct which is objectively necessary or produces efficiencies which outweigh the negative effect on competition. It is vital that consumer benefits, efficiency gains and legitimate commercial objectives are documented from the outset. These are likely to play an increasingly important role in investigations into abuse of a dominant position.

CMA publishes merger assessment guidance and EU consults on merger efficiencies

The Competition and Markets Authority (CMA) published guidance on its approach to merger assessments on 3 September 2026, with a new section discussing its approach to assessing rivalry enhancing efficiencies.

Rivalry enhancing efficiencies arising from a merger induce the merging parties to act as stronger competitors to their rivals and may offset a substantial lessening of competition. The CMA states that it will place greater evidentiary weight on materials generated in the ordinary course of business, such as operational, financial and strategy detail, rather than those generated specifically for gaining merger approval. It will also take into account documents setting out the merger rationale and other transaction materials as well as considering the merging firms' track record in realising and passing on similar benefits. Consequently, rivalry enhancing efficiencies should be considered as early as possible in the deal process and it should be explicit where these form part of the deal rationale.

Similarly, the European Commission is also consulting on how efficiencies should be considered under its EU-wide merger rules. It intends to finalise its review process in Q4 2026. The draft merger guidelines significantly expand on the Commission’s guidance on merger efficiencies – it now explicitly covers benefits to innovation, investment, resilience and sustainability. There is an expanded section on direct efficiencies, detailing the types of merger synergies that lead to efficiencies (including economies of scale and scope). In addition, the draft merger guidelines introduce a new category of dynamic efficiencies that confer the ability or increase the incentives of merging firms to invest or innovate, and whose benefits may materialise over a longer timeframe. Additional guidance is provided on resilience and sustainability benefits. The draft merger guidelines also provide guidance on how to balance harm and benefits, including for out-of-market and collective benefits of mergers, as well as when the benefits would only materialise later than the harm.

CMA sets out strategic recommendations and calls for urgent action on bid rigging in public procurement

See procurement section.