I have in front of me a letter from Peter Norton of BHAB. The gist of it is that PPL (H) holders will be restricted to a horizontal visibility of no less than 1500m, unless they hold an instrument rating. It follows that flights conducted in viz of less than 1500m must be made under IFR and in consequence the aircraft will require a basic scale of instruments, even when the flight is to be conducted by visual reference. Additionally, in circumstances where IFR compliance is required, the holder of a UK PPL(H) must be instrument rated in line with JAR FCL requirements.
Nothing in the letter about heights AAL. The CAA has published a letter of intent and the Regulatory Impact Assesment (RIA) has been published on the CAA website.
www.caa.co.uk follow the links >Safety Regulation>General Aviation>Information.
I haven't seen the letter of intent or RIA but, as far as I'm aware the changes apply to PPL holders only. Lets face it from 1500m viz to totally IFR can happen b
quick. I still wonder at CPL/ATPL holders being allowed to operate VFR in 800m!
Peter's letter was dated 7th Feb 2007 so the CAA site may have changed by now.