CAP 493 Section 1 Chapter 11
3.3 Flight Rules and Meteorological Conditions
3.3.1 Basic Service is available under IFR or VFR and in any meteorological conditions.
Pilots should be aware that Basic Service might not be appropriate for flight in IMC when other services are available.
I wondered if the removal of the previous obligation of Approach units in Class G to separate IFR flights would encourage 'queue jumping' tactics.
Time will tell I suppose, but certainly on day one, I had my first case of an inbound aircraft flying in IMC (clearly stated by the pilot) who elected to receive only a Basic Service. The reference from CAP493 above states that this might not be appropriate; however it is uncontrolled airspace at the end of the day. As an ATCO with over 12 years of APP in Class G, it felt very strange indeed.