At present, PAOC arrangements are set up according to a CAA CAP publication. A Police Air Ops Manual is generated on the basis of that document, rather than JAR-OPS 3.
The CAA have decided that they want all emergency services helicopters to work on the basis of quasi-JAR-OPS 3 standards. HEMS is already included (as commercial air transport), but police is specifically excluded. However, the CAA have decided effectively to ignore this and make all emergency services prepare ops manuals along the lines of JAR-OPS 3. Someone is drafting up some extra bits to add to JAR-OPS 3. I believe police units will be asked to "upgrade" some time next year.
What is not quite clear yet is whether some of the useful exemptions available to emergency services helicopters will be retained.