Ofcom said more than 2 million people who buy only a landline telephone service would see their prices come down towards levels last seen in 2009, after deciding that the market was not working properly.

It said it would also propose safeguards to prevent BT, the country's dominant telecoms provider, from hiking its line rental and landline call costs by more than inflation in future.

"Line rental has been going up, even as providers' costs come down," Ofcom Chief Executive Sharon White said. "This hurts people who rely on their landline the most, and are less likely to shop around for a better deal. We think that's unacceptable."

In recent years Britain's communications market has evolved to allow customers to buy several services - TV, broadband and telephony - in one package. That has allowed firms to provide a range of different offers, but the price of the landline-only service has gradually risen.

Ofcom believes that those customers most likely to take just a landline are the elderly or vulnerable who rely on the service and who are unlikely to shop around for a better deal.

Under its plan, those BT customers with only a landline will see their bill fall from 18.99 pounds per month to 13.99 pounds.

Ofcom said it would consult the industry on its plan in a review that closes on May 9.

(Reporting by Kate Holton, Editing by Paul Sandle)