“…Adjudication Officer v Foster [1993] A.C. 754; Wandsworth London Borough Council v Winder [1985] A.C. 461 and in particular at pp.509–510, per Lord Fraser of Tullybelton; Mercury Communications Ltd v Director General of Telecommunications [1996] 1 W.L.R. 48and in a…”
“…PML relied on the well-known principle exemplified by Wandsworth LBC v Winder [1985] A.C. 461 that the invalidity of a public body’s prior action may be relied upon as a defence. This principle has been relied on by tribunals in penalty appeals which ha…”