<P> In the appeal, it had been argued by Quebec that interjurisdictional immunity did not apply where a law raises a double aspect . Although it was not necessary to decide that question, it was stated that the argument misapprehended the doctrine of interjurisdictional immunity: </P> <P> The interjurisdictional immunity analysis presumes the validity of a law and focuses exclusively on the law's effects on the core of a federal power...What matters, from the perspective of interjurisdictional immunity, is that the law has the effect of impairing the core of a federal competency . In those cases where the doctrine applies, it serves to protect the immunized core of federal power from any provincial impairment . </P> <P> The doctrine of federal paramountcy would not apply in this case . </P> <Ul> <Li> Paramountcy may flow either from the impossibility of complying with both federal and provincial laws or from the frustration of a federal purpose . Here, there was no operational conflict, since the federal legislation did not require the construction of an aerodrome and it is possible to comply with both the provincial and federal legislation by demolishing the aerodrome . </Li> <Li> There was also no evidence establishing that a federal purpose regarding the location of aerodromes was frustrated by the provincial legislation . The federal regulations provide that the Minister responsible may determine that the location of each registered aerodrome is in the public interest, but they do not disclose any federal purpose with respect to the location of aerodromes . </Li> </Ul>

Quebec (ag) v canadian owners and pilots association