Hi, and
to the forums.
You would need a new router.
Your router has a built in ADSL modem and NTL dont use this type of technology. NTL provide you with a cable modem instead.
Your cable modem will go into a normal cable router so that is what you need, and not an ADSL router.
Plenty of cable routers reccomended here:
http://cableforum.co.uk/board/showthread.php?t=33018
Most will cope with 10mb speed, but to be sure post the one you intend to buy and we'l check it.