Surely the UK should just adopt the ICAO "cleared ILS approach" phraseology, and if necessary change the procedures at Heathrow to take into account the helicopter routes.
I take it that the "..very low altitude.." described by Heathrow Director is the platform level for the approach (I think 2500 feet on westerlies - correct me if I'm wrong!). Assuming that most aircraft will join final at around ten miles, why not renotify the platform level as 3000 feet (for example)?
If there is something blindingly obvious at LL that i've missed, then forgive my ignorance; we've looked at this (albeit informally) in some detail at our unit, and the ICAO standard does seem the most sensible.
That said, our MATS 2 says the same as others in th UK, so don't expect to be "cleared for the approach" at EDI anytime soon!