Cheers guys, I feared as much. Luckly it just goes over a small cul-de-sac and the new fixing is towards the pole so this helps. I can't get BT to relocate it until the new wall is there and the new wall can't go up until the cable and fixing are moved! I'll try and carefully relocate it to one of the scaffold poles and then get BT out (hopefully before 2013) to fix it back properly. I'll try and keep a phone connection but you wont hear if I don't as I wont be on line!
More money flying off to the good old service providers for probably a 1hr job
.