Virgin Media has called into question the advertised headline speeds touted by copper-based (ADSL) broadband suppliers as a result of a new study by Ofcom.
In association with broadband testing company SamKnows, the communications regulator conducted 60 million speed tests at 1,600 households over a five-month period to learn the true speeds provided by Britain's biggest internet service providers (ISPs).
Cable broadband supplier Virgin Media was found to top the list, with typical speeds of 8.1Mb to 8.7Mb on its 'up to' 10Mb service, while ISPs using ADSL technology posted significantly slower speeds for their 'up to' 8Mb services.
These speeds ranged from an average of just 3.2 to 3.7Mb for Tiscali UK, to between 4.1 and 5.1Mb for O2's home broadband package.
In response to the findings, Virgin Media warned that the claims of most ADSL broadband providers are "not to be trusted".
A spokesperson for the provider said: "Virgin Media delivers more than any other major ISP - even our cheapest broadband tier delivers double the average of our major competitors - and we are committed to making all of our marketing better reflect the actual experience our customers get."
Top 10 Broadband's Jessica McArdle predicted: "Today's Ofcom report shows that the days of 'up to' speeds may be numbered. We're expecting real average speeds for ISPs to start becoming the norm by the end of this year."
Last week, the broadband supplier announced that it has become the first UK ISP to embark on a partnership with SamKnows to test the real-world performance of its broadband network.