“The principle that legitimate expectation should be protected is now well established as a ground for judicial review. For this principle to apply, the general requirements are: (1) the claimant has an expectation of being treated in a particular way favourable to the claimant by the defendant public authority; (2) the authority has caused the claimant to have the expectation by words or conduct; (3) the claimant’s expectation is legitimate; (4) it would be an unjust exercise of power for the authority to frustrate the claimant’s expectation. Although it has sometimes been said to be a requirement also that the claimant has relied to its detriment on what the public authority has said, the law now seems to be clear that such detrimental reliance is not essential but is relevant to the question of whether it would be an unjust exercise of power for the authority to frustrate the claimant’s expectation.”
“Consistency of treatment is, as Lord Hoffmann observed in Matedeen v Pointu[1999] 1 AC 98 , at para 9 “a general axiom of rational behaviour”
“….grounds of judicial review are carefully crafted in public law garb but when the outer garments are peeled back the true substance is revealed. And that true substance is the meat and drink of the statutory review and appeal procedure.”