Open Letter: Why the CMA Must Enforce the DMCCA

TL;DR: Today, Open Web Advocacy joins 17 businesses, industry bodies, public figures and civil society organisations including Mozilla, Vivaldi, DuckDuckGo, Coalition for App Fairness, Institute for Public Policy Research (IPPR), Proton and the UK consumer organisation Which? and others in an open letter to the UK Government and the Competition and Markets Authority (CMA).

Effective enforcement is vital to ensuring that browsers, browser engines and web apps can compete on fair terms.

Together we call for more ambitious and urgent enforcement of the Digital Markets, Competition and Consumers Act (DMCCA).

The Digital Markets, Competition and Consumers Act 2024 gives the UK Competition and Markets Authority new powers to regulate major digital firms that are designated as having strategic market status. These firms may be subject to tailored conduct requirements aimed at preventing unfair practices, promoting competition, and protecting users and business customers.

Apple and Google have now been designated under this regime. In effect, the DMCCA is the UK’s answer to the EU’s Digital Markets Act, but it is less prescriptive. That flexibility could be a strength, giving the CMA room to design targeted and effective interventions, but it is also a risk: the law’s impact will depend heavily on the CMA’s willingness to use its powers decisively.

In some respects, the DMCCA could prove even more powerful than the DMA. That is why the CMA’s initial reliance on weak voluntary commitments, and some of its recent comments questioning the need to always push for competition are so concerning.

Equally, it does not require us to take an overly narrow, ideological stance in defence of competition. In the current economic, political and geopolitical context, that would not, in my view, discharge our mandate in the UK’s best interests. [...] Not competition for its own sake, but in service of national priorities – specifically driving economic growth and improving household prosperity. Not competition above all else, but as a powerful tool to deploy alongside other levers – like tax, subsidy, investment, or regulation. [...] Sarah Cardell - the CMA’s Chief Executive
(emphasis added)

It has also been suggested by the former chair of the CMA Marcus Bokkerink that the CMA has effectively ceased enforcement of the DMCCA on US-based tech giants:

I was asked if the current UK government approach to competition policy has had a chilling effect on enforcement. The short answer is two-fold. In anything to do with digital infrastructure, digital services, and AI involving US-HQd technology platform businesses with overwhelming market power, enforcement has effectively ceased (in turn discouraging innovations and alternatives to economic dependency from developing). Marcus Bokkerink - Former Chair of the CMA
(emphasis added)

However, promoting competition for the benefit of consumers is not optional. It is the CMA’s core statutory duty under the Enterprise and Regulatory Reform Act 2013:

(1) There is to be a body corporate known as the Competition and Markets Authority.
(2) In this Part that body is referred to as “the CMA”.
(3) The CMA must seek to promote competition, both within and outside the United Kingdom, for the benefit of consumers. Enterprise and Regulatory Reform Act 2013 - Part 3
(emphasis added)

The most recent government strategic steer made clear that free and fair competition, alongside consumer protection, is a driver of growth, innovation, productivity and investment in the UK:

The primary mission of this government is economic growth. Free and fair competition and effective consumer protection support growth by driving forward innovation, increasing productivity, and encouraging investment – including international direct investment – into the UK. Strategic steer to the Competition and Markets Authority
(emphasis added)

Competition enforcement should not be treated as a cost to growth, but as one of the tools that makes high growth possible. When dominant firms are required to compete on fair terms, markets become more dynamic, innovative businesses have room to scale, and consumers and business customers benefit.

The OECD and IMF have both recognised the link between competitive markets and stronger productivity, investment, and innovation. The Government’s own DMCCA impact assessment projected billions in future benefits, and the CMA’s first decade of work has already delivered more than £20 billion in direct consumer savings.

Our view is that enforcement action has been quite weak,” Byrne said. “We are concerned about whether you might pull your punches and leave the new powers available to the CMA unused,” he added later, referring to the Digital Markets, Competition and Consumers Act, which came into effect last year and has significantly expanded the regulator’s powers, enabling it to give companies specific regulatory rules and engage in proactive enforcement, impose stronger penalties, and directly enforce consumer protection laws. Liam Byrne - UK MP
(emphasis added)

Competition can be the key mitigation for the UK’s digital dependency [...] With the Digital Markets, Competition and Consumers Act [...], but slow implementation and weak early enforcement risk squandering a rare pro-growth and pro-SME opportunity. [...] The potential for huge economic growth from our tech sector is there, but competition is key. If competition flourishes, we will see more innovation, improved services and lower costs for consumers. [...] Only a small number of designations have been made so far. For Google’s and Apple’s mobile ecosystems, the CMA has relied on non-binding “commitments” rather than imposing binding conduct requirements. These non-binding commitments have no clear statutory basis under the 2024 Act, carry no legal consequences if breached and are not contemplated anywhere in the CMA’s published guidance. Their use risks weakening the regime and forcing the CMA to restart enforcement if firms fail to comply, which is precisely the outcome that the last Government sought to avoid. Peter Fortune - UK MP
(emphasis added)

The CMA should also heed the directive in the Government’s strategic steer and ensure that the many concrete consumer and business benefits already arising from the Digital Markets Act in the EU are replicated in the UK. UK consumers and businesses must not be left behind.

The CMA should consider the actions being taken by competition and/or consumer protection agencies in other jurisdictions internationally, and, where appropriate, seek to ensure parallel regulatory action is timely, coherent and avoids duplication where these parallel actions effectively address issues arising in markets in the UK. Strategic steer to the Competition and Markets Authority

# Mobile Ecosystems Study and Market Investigation Reference

The CMA has been investigating Apple’s restrictions on browsers and web apps for five years. This started on the 15th June 2021, when the UK’s Competition and Markets Authority (CMA) launched a market study into mobile ecosystems. This study correctly identified that Apple was undermining browser and web app competition via its ban on third-party browser engines.

On the 22nd of November 2022, the CMA announced it had decided to launch a Market Investigation Reference into Mobile Browsers and Cloud Gaming.

Market Investigation References (MIRs) are only started when the CMA has “reasonable grounds for suspecting that a feature or combination of features of a market or markets in the UK prevents, restricts, or distorts competition”. They are a significant and expensive undertaking:

Full market investigation references tend to be used only in cases where competition problems are considered to be particularly significant and/or warrant further detailed investigation, and where the stronger and more wide ranging powers available to the CMA are considered to be more appropriate. Ashurst - Guide to the use of market studies in UK competition law
(emphasis added)

Once an adverse effect on competition has been confirmed, MIRs are intended to fix the issue:

Following a market investigation, the CMA can take remedial action itself through exercising its order - making powers or by accepting undertakings from relevant parties. Alternatively, it can recommend (but not require) that remedial action should be taken by others such as government, regulators and public authorities. Section 134(6) of the EA02 requires the CC [Competition Commission] to take into account the following in considering potential remedial action: "the need to achieve as comprehensive a solution as is reasonable and practicable to the adverse effect on competition and any detrimental effects on customers so far as resulting from the adverse effect on competition". Ashurst - Guide to the use of market studies in UK competition law
(emphasis added)

The final report made extensive findings against Apple’s ban of third-party browser engines:

• We conclude that the WebKit restriction means that there is no competition between browser engines on iOS.

• We also conclude that the WebKit restriction harms competition in the market for mobile browsers on iOS.

• We conclude that Apple’s WebKit restriction limits the ability of rival browser vendors to improve the performance of their mobile browsers on iOS.

• We conclude that Apple’s WebKit restriction limits the ability of rival browser vendors to innovate and improve their mobile browsers on iOS.

• We conclude that Apple’s WebKit restriction increases costs of rival browser vendors as it requires them to develop and maintain an additional version of their mobile browser, based on WebKit, to serve iOS users.

• We conclude that this reduces the features available to consumers and web developers, and limits effective competition between browser vendors on iOS on security, privacy, and performance.

• We conclude that the WebKit restriction does not give rise to rivalry-enhancing efficiencies in mobile browsers on iOS that would offset the negative effects on competition associated with the WebKit restriction we have identified.

• We conclude that the WebKit restriction therefore limits the features available to users and decreases competition between mobile browsers on privacy features on iOS.

• New features and improvements are a key parameter of competition between browsers. We conclude that by preventing, or making it more difficult, for browser vendors to implement new features and improvements, Apple’s WebKit restriction limits the ability of rival browser vendors to compete on iOS. We have seen evidence of limitations impacting security, privacy, and performance improvements, and support for other features, notably those important for web apps and PWAs.

• We consider that limited competition in the markets for browser engines and mobile browsers on iOS has led to worse outcomes for web developers than we would expect in a well-functioning market. There is evidence that WebKit has been slower to support new mobile browser features, particularly in relation to web apps, and that this is a particular concern for developers interested in more innovative features such as those for web apps.

• We conclude that the evidence demonstrates that Safari has or has had wider and more immediate access to functionalities on iOS than other mobile browsers.

To fix these, their final decision included the following remedies:

(a) allow the use of alternative browser engines on iOS – by removing current* clause 2.5.6 from Apple’s App Review Guidelines, which requires third-party browsers to use WebKit, and refraining from introducing any guidelines with *similar effect in the future; and

(b) provide ‘equivalent access’ to iOS as that which WebKit, Safari or third-party applications have to iOS on fair, reasonable and non-discriminatory (FRAND) terms to browser vendors choosing to use browser engines other than *WebKit (‘alternative browser engines’).

High-level parameters that could be used to assess equivalence of access to functionality include: (a) enabling access in a way which respects the technical architecture of alternative browser engines;

(b) enabling access to all of the current operating system-level features and functionalities that WebKit and Safari currently use;

(c) enabling access to all other current operating system-level features and functionalities that exist on iOS and are available for use by third-party applications, but which WebKit and Safari currently do not use;

(d) enabling access to future operating system-level features and functionalities available to WebKit, Safari, or third-party applications, whether or not WebKit and Safari choose to use them;

(e) enabling access to the required iOS functionality to allow browser vendors using alternative browser engines to install and manage progressive web apps (PWAs) using alternative browser engines; and

(f) enabling access to the required functionality to allow browser vendors using alternative browser engines to check whether their mobile browser has been set as default. MIR - Final Decision - Appendix D
(emphasis added)

The MIR team also explained in extensive detail that they decided that deferring these remedies to be implemented under the DMCCA was the fastest and legally safest path forward.

OWA suggested implementation of a minimum ‘core set of the most critical remedies’ (eg to address the WebKit restriction) at the conclusion of the market investigation. Once the DMCC Act was in force, the DMU could take over responsibility for ongoing enforcement, addressing any remedies that have been ‘bypassed or whose objectives remained unfulfilled’. [...]

...we remain of the view that a recommendation to the CMA Board to use the new DMCC Act powers is an effective and comprehensive remedy to address the AECs [Adverse Effect on Competition] we have identified. [...]

In any event, we do not consider that interventions which the CMA may decide to impose under the DMCC Act powers would necessarily take significantly longer to implement than the remedies which could be imposed via the EA02 remedy-making powers. [...]

We consider that the likelihood of the CMA Board acting on our recommendation* *in a timely manner is high. [...]

Taking all the above considerations into account, we conclude that a recommendation to the CMA Board in the manner expressed in the Our remedy sub-section above is the most appropriate way to address effectively and comprehensively the AECs we have identified. MIR - Final Decision - Appendix D
(emphasis added)

The CMA plans to investigate browser engines and the potential of web apps in the second half of 2026.

We urge the CMA to use its powers decisively to address the many issues identified in both the mobile ecosystems study and the market investigation reference. It must also ensure that Apple is not permitted to offer a compliance solution that prevents the remedies from being effective, as it has done in both the EU and Japan.

# Open Letter

26 MAY 2026

AN OPEN LETTER TO THE UK GOVERNMENT AND THE COMPETITION AND MARKETS AUTHORITY

Standing up for fair competition and real choice online: the UK must seize its opportunity

Rt Hon Peter Kyle MP, Secretary of State for Business and Trade Rt Hon Liz Kendall MP, Secretary of State for Science, Innovation and Technology Sarah Cardell, Chief Executive Officer, Competition and Markets Authority Doug Gurr, Chair, Competition and Markets Authority

Dear Secretaries of State, Chief Executive Officer, and Chair,

The undersigned businesses, industry bodies, and civil society organisations write to urge the Government and the Competition and Markets Authority (CMA) to implement the Digital Markets, Competition and Consumers Act (DMCCA) with the speed and ambition that the UK's digital economy demands.

We write not as a single-issue coalition, but as a broad alliance with a shared belief that the UK must create the conditions for the next wave of challenger businesses to compete on merit and grow.

The DMCCA was passed with overwhelming cross-party support because Parliament recognised that a small number of companies dominate the UK's digital markets – limiting consumer choice, raising barriers for businesses, and stifling innovation. It gave the UK one of the most sophisticated competition tools in the world. It was, rightly, celebrated as a landmark piece of legislation.

We are concerned that this opportunity is at risk of being lost.

The pace and ambition of enforcement is falling well short of expectations behind the markets it was designed to address.

More than a year after the DMCCA came into force, progress has been limited. Key remedies identified in market investigations, such as mobile browsers, search engines, and app stores remain unimplemented. In fast-moving markets, delay compounds the problem. Every month without effective enforcement is a month in which dominant platforms further entrench their positions.

Critically, the approach the CMA takes to remedies now will establish the precedent for the entire duration of this regime. The world is watching. The actions taken in the coming months must be ambitious and swift.

This is especially urgent given the pace of change in AI. AI tools and agents are increasingly embedded in the technologies and ecosystems that the DMCCA was designed to address, including operating systems, browsers and search engines. If existing market failures are not corrected now, they will be inherited by the AI era – extending the dominance of a small number of companies into the next generation of digital services.

# Competition is the foundation of growth and innovation

The Government has made economic growth its central mission. Effectively enforced competition regulation is one of the most powerful tools available to deliver that mission.

Research from the OECD and IMF demonstrates that open, competitive markets drive productivity, investment, and innovation. The Government's own impact assessment for the DMCCA estimated billions more in benefits over the coming years, and the CMA itself has delivered over £20 billion in direct consumer savings over its first decade.

There is a risk that a simplistic framing of "growth versus regulation" obscures this evidence. Targeted competition enforcement is not a drag on growth – it is a precondition for it. Open banking showed what this can deliver: a world-leading fintech sector born from pro-competition intervention.

# The UK’s SMEs, startups, and scaleups cannot thrive on an uneven playing field

Many UK startups and developers build their products and reach their customers through digital bottlenecks controlled by a small number of companies. When those companies lock out competitors, they raise the very barriers the Government's own policies are trying to lower. The CEO of the CMA has acknowledged that competition is essential for scaleups, and the House of Lords has warned that the UK risks becoming an "incubator economy" if it fails to support its most innovative technology companies to grow. Without effective enforcement, that risk becomes a reality.

# UK consumers deserve genuine choice over their digital lives

When digital markets are dominated by a small number of companies, consumers pay the price through reduced choice, lower quality, weaker privacy protections, and fewer opportunities to switch. The DMCCA recognised this. Parliament passed it not only as a tool for economic growth, but as a means of protecting consumers and ensuring they benefit from genuine choice. The CMA's new direct enforcement powers under the Act reflect the seriousness with which consumer protection was taken during its passage.

Many consumers in the UK have never been given a meaningful opportunity to choose the default services embedded in their devices. The DMCCA gives the CMA the tools to change this.

# International leadership is at stake

Jurisdictions around the world are watching the UK closely, and taking steps of their own to spur competition and innovation in digital markets. The UK has the opportunity to learn from these examples – both the successes and failures. If it fails to do so, the UK risks becoming the outlier – a market that built a sophisticated pro-innovation tool and then declined to use it, undermining its broader international credibility.

We urge the Government and CMA to:

• Urgently implement its roadmap of interventions and progress new SMS investigations. Translate the evidence and remedies already identified in market investigations into enforceable conduct requirements without further delay – including urgently implementing its published roadmap of interventions and following through on newly announced SMS investigations at speed.

• Provide clear accountability and transparency. Businesses and consumers need confidence that the DMCCA will be enforced predictably and effectively. Clear timelines, transparent enforcement priorities, and regular reporting on progress would provide that confidence.

• Resource the Digital Markets Unit to match its mandate. The DMU must be equipped to monitor compliance, analyse gatekeeper behaviour, and respond to fast-moving developments in AI and digital markets. Limited resources should not be a reason to deprioritise interventions the DMU has identified as pro-competitive.

• Stand behind the Act. The DMCCA exists because Parliament determined that digital markets are not working for UK consumers and businesses. The Government and the CMA should defend that judgment against inevitable pressure from those with an interest in preserving the status quo.

The prize is significant

A competitive digital market where businesses compete on merit, developers can innovate without being locked into a single company's infrastructure, and consumers have genuine choice over the products and services that shape their digital lives, is not just good competition policy. It is the foundation of an innovative, resilient economy that delivers for the whole of the UK. The DMCCA gives the UK the tools to achieve this. We ask the Government and the CMA to use them.

Yours sincerely,

Balanced Economy Project
Coalition for App Fairness
DMG Media
DuckDuckGo
Ecosia
Epic Games
Form Ventures
Institute for Public Policy Research (IPPR)
Martin Wrigley MP
Mozilla
News Media Association
Online Travel UK
Open Web Advocacy
Professor Philip Marsden
Proton
Telegraph Media Group
Vivaldi
Which?
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