Getting Speech in LightDm

[Rob]

I'm running Debian Jessie with latest updates.
I installed the Mate desktop, and I got orca working on there. However I want to have it start like a regular desktop, with a gui login.
Where do you go to have Orca speak on the LightDm login screen? I have braille, but of course, all it says is "screen not in text mode." That isn't very useful obviously. If you can't get speech going in that display manager, is there a better one to use? I think if you install GDM3 it pulls in the entire gnome environment, which is what I wanted to install Mate for in the first place; to avoid that.
Any tips are appreciated.