<<That one's pretty simple - in the UK ATC is not allowed to offer visual approaches to IFR traffic>>
Presumably a recently introduced rule? My ancient MATS Pt1 says:
12 Visual Approach
12.1 To expedite traffic at any time, IFR flights may be authorised to execute visual
approaches if the pilot reports that he can maintain visual reference to the surface and
a) the reported cloud ceiling is not below the initial approach level; or
b) the pilot reports at any time after commencing the approach procedure that the
visibility will permit a visual approach and landing, and a reasonable assurance
exists that this can be accomplished.
12.2 Standard separation shall be effected between such aircraft and other IFR and/or
SVFR aircraft.
Nowhere does that say ATC is not allowed to offer the procedure and I must have offered thousands during my time at Heathrow. Pilot says: "We have the field in sight", ATC says: "Do you wish to continue visually?".. Pilot agrees so ATC says "Cleared for a Visual Approach..