"Our MEL with one XFER pump U/S dispatch is only possible VFR and safe landing must be possible within 15 minutes on each phase of the planned flight. That makes sense."
Yes, it does make sense, just not a very practical situation for a police aircraft at night tasked to far flung (and fuel-less counties). All UK police flying is VFR, day and night as there is no requirement for flight in IMC.