http://www.cableforum.co.uk/board/63...l#post34412833
I've just done it. It's not a problem. See my post in the above thread.
Additional tip; Book Bethere through Quidco, a cashback scheme, and you will get £55 cashback which covers the connection charge and gives £30 off the BT line install/reinstall.
And for sky, this jumps to a whopping £110 cashback.
Take your pick......