Virgin Media is officially launching its 50Mbit/s broadband service today, claiming the fastest internet connection in the UK for those who can receive it.

The fibre-optic service more than doubles the company's existing top speed of 20Mbit/s, and will initially be available to around 12 million homes across the UK. The number is expected to grow as Virgin Media installs new cables.

The project was given the green light after successful trials in May, in which the company revealed that it had been working with Nortel and Juniper to create a backbone capable of delivering 40Gbit/s traffic on the Virgin Media network over a 350km stretch between London and Manchester.

"Today marks a historic moment for both Virgin Media and the UK," said Neil Berkett, chief executive at Virgin Media.

"As the first ISP to roll out next-generation broadband access, our 50Mbit/s service represents the dawning of a new era of high-speed services in the UK, and is just the beginning of what we hope to offer our customers over the coming years."

Strictly Come Dancing contestant Rachel Stevens will be promoting the campaign for Virgin Media.

Although the company has leapfrogged its rivals with this launch, it is expected to face stiff competition from the likes of BT, which is also running trials of fibre-based broadband.

The Virgin Media 50Mbit/s service will cost £51 per month as a standalone offering, or just £35 when taken with a phone line at £11 per month. Other bundles will be available as well.