I agree with Doug. If there is sufficient time to pull out and start overtaking at the legal speed limit, without causing the car behind to brake sharply then that person will have to do what the rest of us have to do when sitting behind slower moving vehicles that are overtaking the slow ones and that is bring the speed down to avoid collision.

I've been in Penny's situation on that same road - quite often the tailgater is a fair way up the road before I start overtaking, far enough away for me to make my move and get back in lane, at the legal limit, without inconveniencing them, and it's purely the fact that they are going well above the limit that puts them on my tail while I'm still in the overtaking lane.

Sounds like, in your case Richard, that the plod were using their status to excuse their own wrongdoing.