The existing copper network in the UK could provide everyone in the UK with 50Mb/s internet, according to Ofcom.
However, the communications watchdog stresses that this is only 'in theory'.
It found that if the upstream modem was hosted in the exchange then any house within two kilometres of it - which amounts to 18 per cent on average of the total number of households - would be able to get data rates of 50Mb/s.
And even more houses could benefit if the modem was moved into the street cabinet, as then 100 per cent of them would be within two kilometres, and would get the fast connection as a result.
However, Ofcom warns that 'these results are theoretical and do not reflect what could be achieved in practice.'
The problem is that individual factors, like the wiring in a person's home, differ wildly, meaning that the speeds are not realistic.
'Nevertheless, the real value of this study is to suggest an upper limit, given all technical progress possible, of 50Mbit/s, with fibre to the cabinet,' Ofcom concluded.