In R ( Brooke Energy Ltd ) v SOS for BEIS (2018) EWHC 2012 ( Admin ) a Divisional Court has restated the principles as to when there is a non-statutory duty to consult. The circumstances in which the common law will impose a duty on a public authority to consult by virtue of the doctrine of legitimate expectation are threefold. First, where there has been a promise to consult. Second, where there is an established practice of consultation. The alleged practice or promise must be clear, unequivocal and unconditional. A practice must be sufficiently settled and uniform to give rise to an expectation that the claimant would be consulted. Moreover, there must be unfairness amounting to an abuse of power for the public authority not to be held to the practice.
Third, a duty to consult will be imposed where a failure to consult would lead to conspicuous unfairness. However, the duty will arise on this basis only in exceptional situations.