The UK’s Competition and Markets Authority (CMA) has officially referred nexfibre’s proposed acquisition of broadband provider Substantial for an intensive Phase 2 investigation. Marking a swift transition in the regulatory process, the probe is being expedited through the regulator’s fast-track procedure following an explicit request from the merging parties.
The deal, structured under a sale and purchase agreement originally dated February 18, 2026, involves nexfibre Bidco Limited acquiring Substantial Topco Limited and its prominent subsidiary undertakings. The transaction brings several notable independent fiber networks and internet service providers under one umbrella, including Netomnia, Brsk, Brsk ISP, and YouFibre.
The acquiring entity, nexfibre, is a powerful joint venture formed by telecom and investment heavyweights Liberty Global, Telefónica, and InfraVia Capital Partners. Because Liberty Global and Telefónica also jointly own Virgin Media O2, the consolidation of these massive broadband infrastructure footprints has naturally drawn close regulatory scrutiny.
Recognizing the scale and potential competition implications of the deal, nexfibre and Substantial proactively submitted a fast-track reference request on June 11, 2026, shortly before submitting their final merger notice. The CMA concluded that the statutory conditions for skipping the prolonged Phase 1 standard review were met, publishing its formal decision to fast-track the merger on July 1, 2026.
With the Phase 2 process now triggered, the CMA has appointed a dedicated four-person inquiry group to lead the in-depth investigation. The panel will be chaired by Cyrus Mehta, who is joined by Robin Cohen, Ashleye Gunn, and Crispin Wright.
Under the strict terms of reference mandated by the Enterprise Act 2002, this panel is tasked with answering two core questions. First, they must verify that the arrangements in progress will officially result in a relevant merger situation. Second, they must determine whether the combined entity will lead to a substantial lessening of competition within any telecommunications or consumer markets inside the United Kingdom.
The inquiry group has been given a clear regulatory timeline to conduct its deep dive, collect industry evidence, and draft its final report. The CMA has set a hard deadline of December 15, 2026, to publish its final findings and decide whether the multi-million-pound broadband merger can proceed as planned, require major remedies, or face a total block.
