A brief Oxford law dictionary entry on Wednesbury unreasonableness mentions that
recent cases indicate that the standard of unreasonableness may be applied with varying degrees of stringency. In cases involving matters of government policy or public expenditure, the courts are reluctant to intervene and tend to apply a more stringent standard of unreasonableness, referred to as super-Wednesbury. A less stringent standard is applied in cases where human rights are at issue, referred to as sub-Wednesbury (R v Ministry of Defence, ex p Smith  QB 517 (CA).
What is the relevant case law for super-Wednesbury and the criteria it set out? (The source ony cites something for sub-Wednesbury.)