Call CIC for a definitive answer.
I would think there are two answers though (and conflicting); if your spouse attempts entry and states he is married and joining his wife then theoretically he will be allowed entry and you will be on the hook for three years. If he states that he is still married but not joining you because the marriage has broken down then there may be an issue BUT unless you have filed for divorce there is the argument that he could answer that he is intending to reconcile etc.