Hi Katie, I did ask the question today and there was no definitive answer. The interviewer said their is usually 10 to a course but they are typically multi depot as well, so Newcastle, London etc and classroom training is based at York. So there may be 1 candidate from Newcastle, there may be more.
They are potentially looking at a training school starting October/November time and are currently interviewing 25 candidates. Those who are successful in their DMI will go on to do the OPC tests. I did my OPC tests last year and passed to enhanced but whether that still passes for LNER, I don't know. If they want me to do them again, then so be it.
With regard to the actual interview, the 2 driver managers who interviewed me were great, they made me feel comfortable and all in all it was as good an experience as you can expect. Hopefully I did enough to progress but I'm under no illusions that I am fortunate to have made it this far as I'm sure the competition is very high.
@mechanic2 not sure what time you had your interview, mine was 10 to 11 but hopefully it went well for you. There was someone else going in straight after me so they're not hanging around, which is good.