Break it up..
"all fibre work has been done / will be done since BT became a private company and as far as I am aware" - no, they're fibre, or will be to the exchange. You won't get any better unless you're a business where BT can make more profit from you by giving you IP-based services - enough hone lines = less cost for BT if you're on fibre, but you don't get lower prices, they just make more cash.
As for the whole EC regulations thing it's all BS - the issues go away if you put it up for tender - we give you xBn, you go away and install the fibre and reap the profits under x conditions - as long as it's for tender i.e. anybody including BT and like, even comcast could come and do it there's no issue. The problem with that is OFCOM and the government like to spend as much time as possible protecting BT and it's shareholders so we couldn't possibly do that.
You could even break the country up and put fibre up for tender - everywhere that's fibre has their BT exchange ripped out and killed, and a company could bid on certain sections and build a network, in return for certian capacity and pricing structures and even SLAs.
Oh wait we have that - it's called the UK cable network pre-NTL. With all the bitching about NTL/VM, it's easy to forget that it's an experiment that worked well until the VM days which could be repeated if the removal of BT and a bit of infrastructure cash is in the offing (which should have happened from day one), and it would be well accepted if fibre connections are on the table.
If you broke it down you could possibly open the door up for people like VM to come in and fibre properly - their network is in place so it'd be cheaper for them to do it, a little more still for BT but there would be nothing stopping them bidding also.