“Legal set-off does not affect the substantive rights of the parties against each other, at any rate until both causes of action have been merged in a judgment of the court. It addresses questions of procedure and cash-flow. As a matter of procedure, it enables a defendant to require his cross-claim (even if based upon a wholly different subject matter) to be tried together with the plaintiff's claim instead of having to be the subject of a separate action. In this way it ensures that judgment will be given simultaneously on claim and cross-claim and thereby relieves the defendant from having to find the cash to satisfy a judgment in favour of the plaintiff (or, in the 18th century, go to a debtor's prison) before his cross-claim has been determined.”
“…although a right of set-off is a defence, with all the legal consequences which follow from it, in practice the exercise of a right of deduction or set-off is essentially a provisional act. It decides nothing finally. Its exercise simply operates as a temporary retention of an economic asset by the party exercising the right, and the temporary deprivation of the other party of that asset. For the exercise of the right does not prevent either party from subsequently proving his claim or cross-claim, and so does not affect the final resolution of the fundamental dispute. … Even so bearing in mind the characteristics of the right, it is in my judgment implicit in its very nature that it should only be exercised in good faith on reasonable grounds,”
“The deduction of$30,000 , unaccepted by the [owners], conferred no legal rights, and could not alter the legal position. After it, as before, the [charterers] had a disputed – and unquantified – claim against the [owners]: after it, as before, if they wished to pursue and to quantify this claim, they had to bring a suit for damages, or to refer the matter to arbitration. By failing to commence a suit before May 1974, a necessary condition to the survival of their claim, they contractually agreed to discharge it.”
“If one of the two liabilities is in one currency and the other is in another currency (whether both foreign or one foreign and the other sterling) two questions will arise. First, to what common currency should the amounts of the two liabilities be reduced in order to effect set-off? Secondly, at what date should such reduction to a common currency, and the set-off which follows it, take place? My provisional view on these questions, without having had the benefit of argument upon them, is that the currency of the lesser liability should be converted into the currency of the greater liability, and the set-off then effected at the date on which the amounts of the two liabilities are established by agreement or decision. Judgment should then be given for the amount by which the greater liability exceeds the lesser liability in the currency of the greater liability or its sterling equivalent at the date of payment.”
“Those are at first sight powerful arguments, but I do not think that they ought to prevail. In the absence of authority - and Counsel have been unable to find any directly in point - the question must be decided on principle and, to my mind, the relevant principle is that people's rights are not in general changed by litigation about them; the effect of such litigation is only to ascertain and enforce those rights. Accordingly, if but for the interpleader proceedings, the right of Selco or its assigns to receive Selco's share of each payment of Class B remuneration would have arisen when that payment was received by Lloyd's on behalf of Smit, so that Smit would have become entitled to give effect to its right of set-off at the same time, and that is not challenged, Smit's right to calculate the set-off on that basis cannot, in my view, be altered by the existence of those proceedings. The true view is, in my opinion, that Smit's debt to Selco, and Smit's right of set-off, arose when the relevant moneys were received by Lloyd's, and that the interpleader proceedings merely delayed the parties' ability effectively to enforce those rights.”
“(3) The broad criterion for the application of set-off is that the plaintiff's claim and the defendant's claim are so closely connected that it would be inequitable to allow the plaintiff's claim without taking into account the defendant's claim. As it has sometimes been put, the defendant's claim must, in equity, impeach the plaintiff's claim. (4) Set-off of costs or damages to which one party is entitled against costs or damages to which another party is entitled depends upon the application of the equitable criterion I have endeavoured to express. It was treated by May J. in Currie & Co v The Law Society[1977] QB 990 , 1000, as a ‘question for the court's discretion.’ It is possible to regard all questions regarding costs as being subject to the statutory discretion conferred on the court bysection 51 of the Supreme Court Act 1981 . But I would not have thought that a set-off of damages against damages could properly be described as a discretionary matter, nor that a set-off of costs against damages could be so described.”