There are two legitimate ways to view the proposed acquisition of Substantial Group by nexfibre.

One is strategic and financial. The UK fibre build cycle has been capital-intensive. Consolidation in infrastructure markets is not unusual once heavy expansion phases mature.

Scale can improve capital resilience, funding flexibility and long-term sustainability. In that sense, the transaction fits a recognisable pattern seen in infrastructure markets once initial build momentum begins to slow.

The other lens is competitive.

Simon Holden’s concern about footprint overlap goes directly to market structure. If a substantial proportion of Netomnia’s network overlaps Virgin Media O2’s footprint, consolidation reduces the number of independent infrastructure options in those areas. That is not rhetoric; it is arithmetic.

The relevant question is whether that structural change alters competitive behaviour in practice.

It is worth acknowledging plainly what the alternative networks have achieved. CityFibre and Netomnia have built meaningful platforms in a relatively short period of time. That is not trivial.

Simon and Greg Mesch, CityFibre’s founder, were central to catalysing the modern fibre build cycle in the UK. Under Callum Dick’s chairmanship and Jeremy Chelot’s leadership, Netomnia moved at remarkable pace. The altnets did not grow by accident. They grew because customers saw a better offer.

That pressure changed the market. Pricing sharpened. Speeds improved. Service standards rose. Incumbents accelerated investment. Consumers benefited.

From CityFibre’s perspective, the concern is therefore straightforward: if independent infrastructure platforms are absorbed into incumbent-backed vehicles, will the intensity of that competitive pressure soften over time, particularly in areas of heavy overlap?

That is precisely the type of issue the Competition and Markets Authority (CMA) exists to examine.

Virgin Media O2 and nexfibre will not have approached this lightly.

Transactions of this scale are preceded by detailed competition analysis and careful regulatory assessment. The overlap will have been examined closely and advisers will have tested possible theories of harm.

The CMA will nonetheless form its own independent view. Opinions in the market – including mine – are not determinative. The decision will rest on that magic word – evidence.

Even if clearance is granted, however, the more demanding question begins afterwards.

Approval addresses structure. Competition is experienced through behaviour.

What ultimately shapes outcomes is how pricing evolves in overlapping areas, how wholesale access operates in daily commercial practice, how migration sequencing is managed and whether service standards remain under genuine pressure.

Integration plans will be thorough. The synergy case will be modelled carefully. Governance arrangements will be clearly articulated. That is expected.

The more challenging phase begins when those plans meet live operating conditions.

Competitive intensity does not reside on a coverage map. It resides in day-to-day commercial decisions once integration begins. It is shaped by pricing discipline, by how actively churn is defended, by how neutral wholesale access feels to retail partners, and by how rationalisation is sequenced without eroding customer experience.

Structure defines the framework. Behaviour determines how competitive the market feels.

The durability of the pressure that the altnets introduced will be shaped less by transaction headlines – and more by how the combined platform conducts itself in practice.

That is not a judgement about this transaction. It is simply how infrastructure markets evolve.

Consolidation may strengthen scale. Whether consumers continue to experience the benefits of competition will depend on what happens next.

About the author

David Hilliard is founder of Mentor, specialists in strategic program execution.

You can call him on 0118 359 2444 or email david.hilliard@mentoreurope.com.