For many years, similarities have been noticed between the motivations for, and the methods of, controlling the exercise of discretionary powers on the one hand, in public law and, on the other hand, in contract law. There has, however, been much disagreement about how far the two processes should aligned, and whether the grounds of review in public law should be extended into the contractual domain. In Braganza v BP Shipping Ltd  UKSC 17, the UK Supreme Court sought a high degree of alignment through the adoption, in a contractual dispute, of public law standards of reasonableness. This article offers a critique of the Court’s arguments in the case and its consequences for contract law.
Chris Himsworth, Transplanting Irrationality from Public to Private Law: Braganza v BP Shipping Ltd, Edinburgh Law Review Volume 23, Issue 1 (January 2019).