In reply to PaulTanton:
We went few weeks back and did as above (as I have on previous visits). Still accessible and we didn't get shot. Other people doing the same.
Although clearly its not in any way a public right of way, just the emergency access to the GCHQ site. You're jumping over a locked gate after all, and strolling round the outside of a rather sensitive listening station!
I think its more accepted now to do as you say, and park at Duckpool and walk north...
Post edited at 16:24