4Ps in a package: CMA launches a consultation on revised merger guidance

On 20 June 2025, the CMA launched a consultation on proposed updates to its merger control guidance. These updates, which follow the new merger rules introduced by the DMCC Act last summer and the introduction of a Mergers Charter¹ earlier in March, are intended to support the implementation of the "4Ps" framework – pace, predictability, proportionality, and process – across the merger control regime. Along with the CMA’s recent call for evidence on merger remedies guidance (with updated remedies guidance planned by the end of the year), it seems that substantial reforms to the UK’s merger regime may be underway. 

The main changes proposed in the consultation cover updates to the pre-notification and phase 1 merger process, updates to the Merger Notice template, and clarifications to the CMA’s approach to jurisdiction and global mergers. 

Pace & Process – Quicker pre-notification and Phase 1 decisions

The CMA’s formal phase 1 investigation is generally preceded by a pre-notification period, in which the CMA gathers information and identifies potential competition concerns. This period varies greatly across cases. By looking to streamline pre-notification activities and updating its Merger Notice template, the CMA aims to shorten the pre-notification period (proposing a KPI of 40 working days) and decrease the volume of internal documents and requests for information at that stage.  

Realising this aim will depend on the parties' ability to address key transaction issues in the initial Merger Notice. The Draft Revised Guidance therefore envisages that parties provide slightly more detail regarding the transaction at the notification stage. The Draft Merger Notice Template will therefore be updated to include additional questions, including around how commercial decisions by the parties are made and how the merger was agreed and approved.  

The Draft Revised Guidance also envisages more constructive engagement between the CMA and merger parties in the course of pre-notification, through teach-in sessions with the CMA case team and subsequent informal update calls. The proposals also foresee the publication of public case webpages at the point of pre-notification to support effective evidence gathering from relevant third parties.  

When it comes to formal investigations, the CMA also seeks to speed up the time in which it announces straightforward clearance decisions, from 35 working days (currently) to 25 working days.  

Predictability – Updates to the jurisdiction tests

The CMA has proposed additional guidance around its jurisdiction to review a “relevant merger situation” under the current legal framework. The CMA has considerable jurisdictional flexibility in determining whether the “material influence” and “share of supply” tests are met in any particular transaction. The CMA’s wide discretion means that it is not always clear to businesses when they should be notifying their deals under the voluntary filing regime.  

These proposed changes aim to help provide businesses with greater predictability over which deals may potentially be assessed by the CMA.  

The Draft Revised Guidance seeks to clarify when an enterprise may be seen to have acquired “material influence” over another enterprise. Factors such as the level of shareholding, rights to appoint board members, and the existence of financial and consultancy agreements may all be taken into account. The proposed updates also confirm that shareholdings conferring voting rights of less than 25% will be unlikely to confer material influence on their own. 

As for the “share of supply” test, the CMA explains that it will likely focus on the criteria listed in the legislation for determining whether the 25% threshold is met, such as value, cost, price, quantity, capacity and number of workers employed. 

While these clarifications are limited to how the current legal tests are applied, the Government has signalled its intention to revise the legal merger jurisdiction tests in the near future.²   

Proportionality – “wait and see” for global deals

Finally, the CMA proposes that it will more likely prioritise for investigation deals which have a UK-specific impact, rather than deals which affect exclusively global markets. In the latter case, the CMA proposes a “wait and see” approach to assess whether merger control proceedings by foreign regulators are likely to address UK competition concerns before prioritising such deals for investigation.  

These proposed changes, though constrained by the existing legislative frameworks, nonetheless reflect the CMA’s proactive response to the Government’s strategic steer towards fostering a more business-friendly regulatory environment. The consultation on the Draft Revised Guidance closes on 1 August 2025.

Footnotes

• [1] CMA, Guidance, “Mergers charter" (12 March 2025) accessed at https://www.gov.uk/government/publications/mergers-charter-how-to-work-with-the-cma-on-a-merger-investigation/mergers-charter#pace.
• [2] UK Government, “The UK’ Modern Industrial Strategy” (June 2025), page 77; HM Treasury, Policy Paper “New approach to ensure regulators and regulation support growth” (31 March 2025) accessed at https://www.gov.uk/government/publications/a-new-approach-to-ensure-regulators-and-regulation-support-growth/new-approach-to-ensure-regulators-and-regulation-support-growth-html/.