If VM implement Phrom(whether its an opt-in or out is irrelevant)should VM be forced to open its network to competitors, especially non-phorm ISP. I believe Ofcom has the power to do just that.
http://www.ofcom.org.uk/
http://www.ofcom.org.uk/complain/internet/
Why should i or any other user of VM be forced to pay £125 to BT, if there was competition within the cable market i could avoid those costs.