Can an existing power of attorney be suspended while a guardianship dispute is before an Ontario court?

Yes, in appropriate circumstances. Where there's a genuine dispute before the court about whether a guardian should be appointed, or where concerns have been raised about how an existing attorney under a power of attorney is acting, the court can grant an interim order suspending or restricting the attorney's authority while the underlying dispute is resolved, rather than leaving the attorney free to continue acting as usual throughout the litigation.

This kind of relief is generally reserved for situations involving credible concerns about the attorney's conduct, a conflict of interest, or a genuine risk to the incapable person's property or wellbeing if the attorney continues acting unchecked — it isn't granted simply because a guardianship application has been filed or because family members disagree with decisions the attorney is making within their authority. Courts will weigh the seriousness of the concern against the disruption of suspending someone who may otherwise be acting appropriately, and will often tailor any suspension to address the specific problem rather than removing all authority outright. If you're concerned about an existing attorney's conduct during a guardianship dispute, raise the issue with your lawyer promptly, since this kind of interim relief is time-sensitive.