Virgin Media plans to upgrade 2.6m customers with 2Mb cable broadband connections to its superfast 10Mb service in May.
The free upgrade follows a similar move by Virgin last year, when the ISP switched those with 4Mb connections to its 10Mb service. From May, Virgin's three fibre optic broadband deals will be available with 10Mb, 20Mb and 50Mb download speeds.
"Our entry-level broadband product is now twice the speed of comparable services and, with our new 10-20-50 range, we clearly offer the highest quality broadband service in the UK," said Virgin's chief executive Neil Berkett.
"Coupled with our recently launched 50Mb service, we are proactively developing the UK's broadband market, driving consumer expectations and the demand for high speed broadband services."
Virgin, which has more than 10m customers in the UK, said the widespread availability of 10Mb connections will allow more people to use BBC iPlayer and other high-bandwidth services, and said the upgrade supports the government's Digital Britain policy agenda.