Apps: Rae would have to resign as interim by October latest if he wants to run. In which case Garneau would have to be interim. Is Carolyn Bennett's French OK? She'd be another good choice for interim if she wanted it.
I'm not sure if this quote still applies, but here's a French professor from the University of Ottawa on Bennett's French as it was in 2006 (when she briefly ran for the brass ring):
"But Knoerr saved her harshest judgement for another Toronto-based candidate, Carolyn Bennett. The Toronto MP had a poor grasp of both vocabulary and grammar. The professor said a francophone "would last about 15 seconds listening to her."-- CTV News