Thanks so much everyone, I really appreciate your replies and it's making me feel a little better about the interview.
I am hoping that I can do as you suggest, and briefly explain why I left and remain positive, hoping that they will be able to read between the lines. Although I am getting over it and trying to learn from my experience and put it behind me, my confidence has been very much shaken so I am hoping that they interviewers will not be too aggressive and I can maintain my composure and remain positive which is more like my normal character!
Unfortunately I am new to this country and so do not know many people in a senior position who can provide references, although other research colleagues in the lab I was in have offered to provide character references if I need them which is great.
Do you think it would be helpful for me to offer the contact details of a colleague who is at the same level as me (senior postdoc) to provide a reference specifically for this, or would it really need to be someone in a more senior position?
The only other person I know at a more senior level who was aware of the situation is the bullying advisor at the university (who is also a senior academic in a different faculty) but I feel I can't really use that person for a reference as this would come across as quite negative that I made an official report about bullying behaviour.
I agree with your comments about the training system Jim, it feels to me like a real David and Goliath situation being up against someone who is very powerful and feeling so powerless myself. It would be nice if this could be changed in future generations but I fear it will not, as people get promoted based on their publication output and grant success and not on whether they are actually capable of interacting with and managing people. At any rate, I definitely have a list of behaviours to avoid if and when I ever have a research group of my own!
Thanks again :-)