Just to be clear, I was stopped at the give way line, and the lane to my right was clear, meaning that I should be able to pull out with no problems. At that stage the (I assume) police car appeared with blue lights, but no siren until it was passing in front of me. Visibility to the left was not brilliant, and had I been a couple of seconds earlier I would have started pulling out and seen the vehicle approaching the wrong way in my lane and stopped. However, because of its speed I doubt that it could have stopped in time.
Dave