News 

Under the consultation, which is due to run until 25 June, Ofcom will assess the practical benefits of deploying ultra-fast broadband through existing networks such as water and energy.

In theory the practice could speed up the deployment of fibre and put a dent in the estimated £15 billion costs, as providers wouldn't need to dig up the streets.

"We must be sure we are not missing a trick here," says Ofcom chief executive Ed Richards, announcing the review. "We know that lots of the costs are in the civil engineering and this is civil engineering of a very similar kind."

Ofcom says it will also be looking at the duct networks owned by BT and other telecoms operators. "We need to establish what the position is here and whether or not duct access has a role to play in the development of competitive next-generation access."

Companies such as H20 are already deploying fibre networks through the sewers.