In Arorangi Timberland Ltd v Minister of the Cook Islands National Superannuation Fund (Cook Islands) [2016] UKPC 32, the Privy Council upheld a Cook Island Court of Appeal decision which declared that the superannuation scheme set up by the Cook Islands' National Superannuation Act 2000 (Act) was constitutional.

The appellants sought to prove the scheme was unconstitutional and thus invalid on two points. First, that it involved 'taking' or 'deprivation' in a manner contrary to the Cook Islands Constitution (Constitution). Second, that it was unjustifiably discriminatory contrary to the Constitution.

The first question required an analysis of the proportionality test used in the Court of Appeal. The Board determined that the Court had erred in adopting a 'Wednesbury irrationality' test with respect to the presumption of constitutionality. Instead, they found that the standard of review depends on several factors including the rights involved, the identity of the decision-maker and the nature of the issue. Adopting that analysis, the Board acknowledged that some provisions of the Act would benefit from Parliament's reconsideration, but held that the purported concerns were insufficient to render the Act unconstitutional. They rationalised that the right concerned was important, but mild in comparison to others, and further that the decision-maker was a democratically elected legislature.

The Board concluded that the Act establishing the scheme could not fail on constitutionality, but found that s 53, which had the effect of prohibiting migrant workers from recovering their employer's contributions to the scheme in specified circumstances, was invalid because it was unjustifiably discriminatory to migrant workers. Lord Sumption dissented in part, stating that the Privy Council did not have grounds to decide on the validity of the social policy underlying s 53, and preferring to declare the Act constitutional as a whole.

See the Court's decision here