Conclusion

In sum, a body of clear rules exists which allows, but also restricts, reference to international legal norms in domestic settings. Conformity with these common law rules has positive value because they are fundamental to a number of basic constitutional goods, from that of upholding parliamentary sovereignty, to checking executive excesses, to ensuring respect for the rule of law. But these rules should not constrain able advocates and members of the judiciary, who can and should actively refer to international legal sources both because they represent a vast repository of knowledge and good practices, and because ultimately doing so may help states comply with both their national and international legal obligations.