Mountain Ratings
It appears from the EASA website and the mostly Swiss documents that the Mountain Rating will be required when operating between 5000 and 18000 ft! Ben Nevis hill not that high........
IR's
Nothing in 090/2011 to suggest mandatory IR,s for police ops. In fact, annex iii, Part-ORO, FC200, 202 and 250 indicate the hours requirement for VFR at night,
A valid instrument rating OR
250(a)(2)(ii)
300 hours of flight time on helicopters, including 100 hours as PIC and 10 hours as pilot flying at night.