Leatherhead
Possibly a Idiot.
It doesn't stop them from moving into the space... but once they've moved into the square, it's no longer a legal square for them to end their move in, and neither is any other square.
You can't end your move in a square without having moved into the square, and once you've moved into the square it's a square within your space, which means it's a square you occupy, which means (according to the premise of the original post, at least) that it's an enemy's square. So you can't end your move in a square without it being an enemy's square... which is a square you aren't allowed to end your move in.
"You aren't in that space until after you move", true, but you can't end your move until after you move either.
-Hyp.
In that case your move would be forced to end in the last square you could occupy, which ends your movement legally because you don't occupy the square until after your move is forced to end.