I think perhaps there is a distinction to be made between 'rabid' labour supporters, people who really want to get the Tories out and the labour party itself.
I come at this as someone who believes that the main priority is to kick the Tories out. I find it hard to reconcile why anyone who hates them and what they have done would cast a vote that could end up helping them. I really wish that we didn't have to do that ... From my perspective if I could right now, I'd probably vote green, but I know if I did, certainly in my constituency, I may as well put my cross in the blue box for all the good it'll do. I wish we had a system (and would vote for it in a heartbeat) where we could all vote the way we would like and it would count, but we have an archaic system that doesn't represent the population... But we can only work with what we have, no matter how that sucks.
That's the way I see it anyway.