Thought I would let you know that I got the situation satisfactorily resolved. The electrical contractor arrived early this morning as originally planned, inspected & tested all the circuits, installed a new earth & cross bonded all services & finished it all of with a nice shiny new C/U. All we have to do now is get the main contractor to finish of the conservatory wiring & connect to the new C/U. Great result, thanks for all the help.