To all who asked, the reason why we can't use "cleared for the ILS" is because some pilots interpreted that as a clearance to descend to very low low altitudes many miles from touchdown. At Heathrow there is a great deal of other traffic flying around under our ILS approaches which has to be protected so our regulators decided that we can only tell pilots to establish on the loc.. and then descend on the ILS. Personally I still think that it is open to misinterpretation but I don't make the rules!!
And to Flapsone.. since this new phraseology was introduced many years ago I've never "cleared" an aircraft for any type of approach at Heathrow so I wonder how they got down!!!