“ … Henderson v Henderson abuse of process, as now understood, although separate and distinct from cause of action estoppel and issue estoppel, has much in common with them. The underlying public interest is the same: that there should be finality in litigation and that a party should not be twice vexed in the same matter. This public interest is reinforced by the current emphasis on efficiency and economy in the conduct of litigation, in the interests of the parties and the public as a whole. The bringing of a claim or the raising of a defence in later proceedings may, without more, amount to abuse if the court is satisfied (the onus being on the party alleging abuse) that the claim or defence should have been raised in the earlier proceedings if it was to be raised at all.”
“ … an appellate court will be reluctant to interfere with the decision of the judge in the judgment he reaches on abuse of process by the balance of the factors; it will generally only interfere where the judge has taken into account immaterial factors, omitted to take account of material factors, erred in principle or come to a conclusion that was impermissible or not open to him.”
“On a question of abuse of process of this kind raised at a preliminary stage such as this, with no oral evidence, it seems to me that the appellate court is often likely to be, and in the present case is, in as good a position as the court below to assess whether the proceedings are or are not an abuse of process.”
“ … Even though the allegations which Mr Koshy raises are of such seriousness and importance, nonetheless the justice system is not bound to provide more than one opportunity to run these issues. That is because the courts have to strike a fair balance between the interests of Mr Koshy on the one hand and of the other parties and the general interest on the other hand. That fair balance in my judgment is struck once Mr Koshy has had one effective opportunity to put his case.”
“(i) Where A has brought an action against B, a later action against B or C may be struck out where the second action is an abuse of process. (ii) A later action against B is much more likely to be held to be an abuse of process than a later action against C. (iii) The burden of establishing abuse of process is on B or C or as the case may be. (iv) It is wrong to hold that because a matter could have been raised in earlier proceedings it should have been, so as to render the raising of it in later proceedings necessarily abusive. (v) The question in every case is whether, applying a broad merits based approach, A’s conduct is in all the circumstances an abuse of process. (vi) The court will rarely find that the later action is an abuse of process unless the later action involves unjust harassment or oppression of B or C.”