Telewest will raise the speed of its broadband packages for the second time this year.
The company will begin implementing its new speeds between December and January, with consumers continuing to pay the existing price of the package they are signed up to. The maximum broadband speed available rises to 4Mb, and no usage cap will be applied.
Telewest Broadband president and chief operating officer, Eric Tveter, said: "This will be the second time this year we have increased the speed of our blueyonder broadband services, doubling the original bandwidth with no increased costs and no introduction of caps.
"This isn't a short-term offer and there are no catches - we're simply giving broadband users what they want, thanks to our advanced cable network. Christmas is a time for giving, so anyone fed up with Scrooge-like behaviour from their ISP knows where to come for faster, unlimited internet access."
All Telewest's existing 750Kb, 1.5Mb and 3Mb blueyonder Internet customers will receive the faster access speeds automatically, with no need for new equipment and no additional fees.
Telewest's 3Mb service migrates to an even faster 4Mb connection, for the £50 a month. Upload speed rises from 256Kb to 384Kb.
The 1.5Mb service will get a boost to 2Mb, still at £35 per month, while the standard service rises in speed from 750Kb to 1Mb and still costs £25 per month.
The entry-level 256Kb service will remain unchanged.