Vodafone has called on BT to be more open with the public about what its G.Fast technology will offer.
BT's infrastructure subsidiary Openreach is currently deploying G.Fast as part of an effort to achieve faster broadband speeds over the existing copper network.
However, research commissioned by Vodafone has found that under BT's current plans, the technology will increase ultrafast coverage for households by less than five per cent.
The study by Point Topic also revealed that just 6.5 per cent of households can expect to receive gigabit-capable fibre-optic cables by 2020 unless action is taken.
Vodafone has therefore urged BT to acknowledge the limitations of its current strategy.
Helen Lamprell, Vodafone's Director of External Affairs, commented: "We call upon BT to be upfront with the British public about its roll-out plans and acknowledge that G.Fast will do nothing to help those stranded on archaic and woefully inadequate broadband today.
"BT is pushing a muddled compromise rooted in the past, while the rest of the world is focused on building the Gigabit Society at light speed over fibre."
Ms Lamprell went on to praise Chancellor of the Exchequer Philip Hammond, who announced in his Autumn Statement that £400 million is to be put towards improving the UK's fibre broadband infrastructure.
The money will be placed in a Digital Infrastructure Investment Fund, with cash shared between fibre broadband providers seeking to expand, while private investors will be asked to match the amount put forward by the government.
A further £740 million will be put towards developing 5G services and a scheme that enables local authorities to bid for fibre connectivity.
"We welcome the government’s move to focus on providing full fibre," Ms Lamprell said.
Vodafone's latest comments come after the Financial Times reported that the company believes Openreach's G.Fast trials breach rules set by industry watchdog Ofcom.
According to the newspaper, Vodafone has called on the regulator to intervene and carry out a proper consultation into this issue.