Should the biggest challenger hit trouble itself, however, its backers could pull out of the sector and lenders to other alt-nets could also start to call in their debts.

“A knock of confidence among investors in CityFibre would spell trouble for the wider alt-net market and their funding positions,” says Matthew Howett, the founder and chief executive of Assembly Research.

“While never too big to fail – and we consider that unlikely – smaller fibre providers almost need them to succeed to secure their own futures.”

Matthew Howett, Founder and Chief Executive of Assembly Research said the CMA’s decision “sets the wheels in motion for a transformation of the UK’s mobile market, and ultimately the experience for consumers”. He added: “We expect positive implications overall, not only for investment in, and the quality of, networks (including standalone 5G), but also for the wholesale customers and consumers and businesses that rely on them.”

Matthew Howett, the founder and chief executive of Assembly Research, said: “A deal of this size and scale was alway going to face intense scrutiny from the CMA, and it was fanciful that it could have been approved without any sort of remedies.”

BT has resumed the transition after forming a new telecare action board alongside local authorities and healthcare providers. However, there is still uncertainty over how many vulnerable customers will be affected by the switchover.

Matthew Howett, founder and chief executive of Assembly Research, said: “Fibre does present resilience challenges itself, particularly in the context of power outages and device compatibility.”

But he added: “The more reliable, resilient and future-proof alternative of fibre and IP communications will ultimately mean fewer faults and outages over the longer term.”

CK Hutchison’s merger of Three Italia with Wind Telecomunicazioni was approved only after the companies agreed to divest assets. More recently, regulators told Orange and MasMovil they had to grant spectrum and roaming access to rival Digi as part of their Spanish merger.

Howett says these remedies have “only compounded the problem” by allowing new entrants into the market just as the existing players are trying to consolidate.

“Where four to three has been allowed to happen, the remedies that you put in place have often just recreated the problem you’re trying to solve,” he says.

Matthew Howett, founder and chief executive of Assembly Research, argues that one of the key purposes of alt-nets has been to push Openreach to build its own network more quickly.

“That dynamic has played out already, it’s happened… so I think once they’ve lit that firework the vast majority of Project Gigabit will happen,” he says.