A couple of corrections to the above posts:
Eggs....Class E airspace indeed exists n the UK, mainly in the big chunk of Scottish TMA around Glasgow and Edinburgh airports. (Belfast also have some).If you read the latest book of Airprox investigations, you'll see one involving a 737 and a microlight in Class E. See and be seen indeed, although this isn't always appreciated by IFR crews travelling at 250kt.
And to the PPLs who feel VRF and IFR could be integrated even closer: I am aware of several Airprox reports filed by IFR crews who felt that VFR traffic had got far too close, when in fact the VFR was visual and safely avoiding - either due to TCAS or crew interpretation, "safe separation" depends on which plane you're sitting in....