Sometimes maybe, although much would depend on the circumstances prevailing in the particular organisation.
Union member is usually perfectly fine - done it myself - even to point of negotiating with reps / officials of same union I was in membership of but that's at least potentially problematic, as much more so might be adopting a much higher profile as a union rep - not least because your employers might be more than a little miffed!
Agree with you David, I have been member and negotiated with my own unions. I have asked to take Learning Rep role and working in Rep role could be seen as problematic!! Despite being fully balanced and acting with neutrality and morality, I can be seen as biased!
We have certainly had HR people as union members without there being an issue, though as Stephen says, need to be mindful of potential conflicts of interest. I would have a massive conflict if I were in one of our recognised unions and was called out to strike - mainly because I manage the union relationship in my organisation and deal with the reporting and comms of strike action which I couldn't do if I were called to take action. Which, as a union member, regardless of how I may vote, I feel strongly that that's part of being a union member.
