I have already provided some very good reasons why volunteering while job hunting is a good idea. I really do enjoy it very much, and given the situation, it would be the perfect job to have while trying to mount the proverbial career ladder, if only it was a paid position.
Well, I have been informed that there may be an opportunity to get paid for some of my hours at the charity bookshop because a couple of the paid staff need to cut their hours. While this is not yet definite, it demonstrates the unexpected opportunities that can arise out of putting your heart into something you enjoy. So, even though this is still not confirmed, and even if it doesn't work out, I thought I would mention it.
I also thought I would mention this for anyone else who is volunteering in the UK while job hunting. Most places offering volunteer positions know that volunteering is often a CV filler, but this is a government programme that also offers official recognition for volunteering.