(1)  A public or other authority is not liable in proceedings in respect of a claim to which this Part applies to the extent that the claim is based on the failure of the authority to exercise or to consider exercising any function of the authority to prohibit or regulate an activity if the authority could not have been required to exercise the function in proceedings instituted by the claimant.

(2)  Without limiting what constitutes a function to regulate an activity for the purpose of this section, a function to issue a licence, permit or other authority in respect of an activity, or to register or otherwise authorise a person in connection with an activity, constitutes a function to regulate the activity.