As part of my feedback after a rather nice interview day at a lovely school (didn't get the job...), the headteacher advised me to find a different referee. I was quite upset obviously, as I believe I might have got the job had my reference been more supportive. It wasn't bad, it just wasn't very good either, I think. There was an issue at my last school, some might call it a 'personality clash' (and I wasn't the only staff member concerned), whatever - there is no point going into it now. I have asked the deputy headteacher, who I got on well with, if she would be my referee instead, but she is leaving at Christmas and has said no. I'm working as a supply teacher and hope that at some point I will get a booking which might be longer than just a few days, and that might give me a chance to use a different referee. My question really is: how long do I have to work at a school before I can ask them if they would provide me with a reference? And would this reference, if it's only for a supply position, be better than a lukewarm reference from my last school? By the way, I have a very good reference from the previous post as well.