I'm with Sykocus and Cripes on this one.
Try standing up in court after a nasty, saying "we don't separate VFR from IFR in Class D".
In the UK, I think CAP493 gives pretty clear guidance on this really:
Extract from CAP493 - Section 3 - Chapter 4 - Integration of VFR Flights with IFR Traffic in Class D CTR/CTA/TMA:
(My bold).
3 Control of VFR Flights
3.1 The minimum services provided to VFR flights in Class D airspace are specified at
Section 1, Chapter 2, paragraph 2. Separation standards are not prescribed for
application by ATC between VFR flights or between VFR and IFR flights in Class D
airspace. However, ATC has a responsibility to prevent collisions between known
flights and to maintain a safe, orderly and expeditious flow of traffic. This objective is
met by passing sufficient traffic information and instructions to assist pilots to 'see
and avoid' each other as specified at Section 3, Chapter 1, paragraph 2.
3.2 Instructions issued to VFR flights in Class D airspace are mandatory. These may
comprise routeing instructions, visual holding instructions, level restrictions, and
information on collision hazards, in order to establish a safe, orderly and expeditious
flow of traffic and to provide for the effective management of overall ATC workload.
3.3 Routeing instructions may be issued which will reduce or eliminate points of conflict
with other flights, such as final approach tracks and circuit areas, with a consequent
reduction in the workload associated with passing extensive traffic information. VRPs
may be established to assist in the definition of frequently utilised routes and the
avoidance of instrument approach and departure tracks. Where controllers require
VFR aircraft to hold at a specific point pending further clearance, this is to be explicitly
stated to the pilot.
3.4 When issuing instructions to VFR flights, controllers should be aware of the
over-riding requirements for the pilot to remain in VMC, to avoid obstacles and to
remain within the privileges of his licence. This may result in the pilot requesting an
alternative clearance, particularly in marginal weather conditions.
3.5 Approach radar controllers in particular should exercise extreme caution in vectoring
VFR flights – a geographical routeing instruction is preferable. Prior to vectoring, the
controller must establish with the pilot the need to report if headings issued are not
acceptable due to the requirements to remain in VMC, avoid obstacles, and comply
with the low flying rules. Controllers should be aware that pilots of some VFR flights
may not be sufficiently experienced to comply accurately with vectors, or to recover
to visual navigation after vectoring.
There is a fine line between overcontrolling and neglecting your Duty of Care. Always cover your six!