Industry experts have voiced doubts over the rollout of what is claimed to be the fastest domestic broadband service in Britain.

Virgin Media today launched the scheme with claims that it will offer speeds of 50 Megabits per second (Mbps) – double that of its closest rival.

Rachel Stevens, singer and star of Strictly Come Dancing, switched on the service, which Virgin says makes it the first UK Internet Service Provider (ISP) to roll out the next generation of broadband to customers in their homes.

Families will have to pay £51 a month to receive the standalone service, or £35 a month if bought with a telephone line costing £11 a month - not including charges for installation.

However, specialists say they are unsure as to the extent of the high-speed service and how widely it will be taken up.

Aamir Baloch, head of telecoms services at firsthelpline.com - a broadband price comparison site - told The Times: "The Virgin [fibre optic] cables are more up to date so they have managed to make it to 50Mbps - with a copper network the further away from the exchange you are, the more difficult it is to get the headline speeds."

Whether you can get 50 Mpbs with Virgin Media "will be subject to the wiring in your house, the kind of router that you use...and your PC or lap top," Mr Baloch said.

Virgin Media’s fibre optic network covers 12.6 million homes, but currently only 10 per cent of their customers opt for the most expensive 20Mpbs product, with 71 per cent choosing the slower and cheaper 2Mbps option.

Mr Baloch added that faster speeds were necessary because of the changing use of the internet. "We are increasingly doing more and more online now than we used to do just a few years ago... not just confined to a picture or an e-mail but on-demand TV and films, and all these things are bandwidth hungry."

Compared with countries like South Korea, where 100Mbps is the norm, Britain still lags behind on broadband speeds, he said. Virgin’s closest rival for ISP speeds, Bebroadband, offers 24Mbps for £17.50 a month.

The new service advertises download speeds of 11 seconds for a music album and three minutes for a film. Upload speeds will be much slower. Sebastien Lahtinen from the independent broadband news and information site, thinkbroadband.com, said: "There is a question over whether there's enough content out there to test whether it will provide those speeds. But now that 50Mpbs is out there it will incentivise companies to provide more content. At first customers will get very fast speeds but as more people sign up long term, that's when congestion will set in."

Andrew Ferguson, Editor of thinkbroadband.com, said it was unclear how popular the service would be with consumers. “If within 18 months Virgin Media can have 10 per cent of its customers on the 50Mbps product, this is likely to encourage its competitors to push on with next generation investment,” he said.

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