According to the Globe the reason why the CAW left the NDP was:
"Are you ready for this? According to In the Eye of the Storm, the CAW is cutting off ties with the NDP because New Democrats are too right wing. Yes, that's right, Canada's official socialist party, the party led by social activist Jack Layton, is not left wing enough for Buzz Hargrove."Now it all make sense. I mean, Buzz wouldn't want to associate with ANYONE who wasn't left-wing, would he?