"A party who knows of an order, whether null and void, regular or irregular, cannot be permitted to disobey it… It would be most dangerous to hold that the suitors, or their solicitors, could themselves judge whether an order was null and void — whether it was regular or irregular. That they should come to the court and not take it upon themselves to determine such a question: that the course of a party knowing of an order, which was null and irregular and who might be affected by it was plain. He should apply to the court that it might be discharged. As long as it existed it must not be disobeyed."
"It is the plain and unqualified obligation of every person against, or in respect of whom an order is made, by a court of competent jurisdiction, to obey it unless and until that order is discharged. The uncompromising nature of this obligation is shown by the fact that it extends even to cases where the person affected by an order believes it to be irregular or even void."
"The contrasting legal concepts of voidness and voidability form part of the English law of contracts. They are inapplicable to orders made by a court of unlimited jurisdiction in the course of contentious litigation. Such an order is either irregular or regular. If it is irregular it can be set aside by the court that made it upon application to that court; if it is regular it can only be set aside by an appellate court upon appeal if there is one to which an appeal lies."
" ... the order was made by the High Court and therefore has to be treated as a perfectly valid order and one which has to be obeyed until it is set aside. (See the speeches of Lord Diplock in In re A Company [1981] A.C. 374 at p.384 and Isaacs v. Robertson [1985] A.C. 97 at p. 102.)"
"As to point (a), it seems to us that, if the making of a restraining order was outside the power of the Kingston Crown Court on6th October 2000 , then the decision to make one 'amounts to nothing', even though the order is only now being formally set aside: see Halsbury's Laws of England (4th Ed. Reissue) Vol. 10, para. 314. The Crown Court is a court of limited statutory jurisdiction, rather than a court of unlimited jurisdiction to which, in at least some contexts, the principles in Isaacs v. Robertson[1985] 1 AC 97 might apply. Further, we are concerned with a criminal context, in whicharticle 7 of the European Convention on Human Rights would, if anything, increase the problems which would be involved in upholding a conviction for an offence of acting contrary to an order which the court, a public authority, had no jurisdiction to make and which this court is now setting aside. We say no more on point (a), in view of the very limited submissions addressed to us on it."
"It cannot be too clearly stated that, when an injunctive order is made or when an undertaking is given, it operates until it is revoked on appeal or by the court itself, and it has to be obeyed whether or not it should have been granted or accepted in the first place."
"Very different considerations apply in the present context. First, the normal rule in relation to an order of the court is that it must be treated as valid and be obeyed unless and until it is set aside. Even if the order should not have been made in the first place, a person may be liable for any breach of it committed before it is set aside."