Ouch flaps! A public nut challenge...
I have spoken to CHIRP, who were very friendly and helpful, but are uncertain as to whether the issue is not an IR one. They suggest the union as an initial contact point, and I have made an approach.
I've edited this post as it contained a direct quote from a company information notice, that I may not have had rights to publish, and have therefore removed.
As I've now got to try and raise some difficult issues without getting identified and fired, I'm not going to post any more on this thread, and will request that it be locked down. However thank you all for your feedback