51. (a) No appeal shall be permitted to the King in Council from a decision of the Supreme Court upon any question, howsoever arising, as to the limits inter se of the constitutional powers of the Commonwealth and those of any Province or Provinces, or as to the limits inter se of the constitutional powers of any two or more Provinces, unless the Supreme Court shall certify that the question is one which ought to be determined by the King in Council.
(b) The Supreme Court may so certify if satisfied that for any special reason the certificate should be granted, and thereafter an appeal shall lie to the King in Council on the question without further leave.
(c) Parliament may make laws limiting the matters in which such leave may be asked, provided that such laws do not impair any right which the King may be pleased to exercise by virtue of His Royal prerogative to grant special leave of appeal from the Supreme Court to the King in Council.