Cause of Action in UK Law

A right to obtain an interlocutory injunction is not a cause of action. It is dependent upon there being a pre-existing cause of action against the defendant arising out of an invasion, actual or theatened by him, of a legal or equitable right of the plaintiff for the enforcement of which the defendant is amenable to the jurisdiction of the court. The right to obtain an interlocutory injunction is merely ancillary and incidental to the pre-existing cause of action.

Cause of action estoppel arises where the cause of action in the later proceedings is identical to that in the earlier proceedings, the latter having been between the same parties or their privies and having involved the same subject matter. In such a case the bar is absolute in relation to all points decided unless fraud or collusion is alleged, such as to justify setting aside the earlier judgment.

That is to adopt too dogmatic an approach to what should in my opinion be a broad, merits-based judgment which takes account of the public and private interests involved and also takes account of all the facts of the case, focusing attention on the crucial question whether, in all the circumstances, a party is misusing or abusing the process of the court by seeking to raise before it the issue which could have been raised before.

A cause of action is simply a factual situation the existence of which entitles one person to obtain from the Court a remedy against another person. But it is essential to realise that when, since 1873, the name of a form of action is used to identify a cause of action, it is used as a convenient and succinct description of a particular category of factual situation which entitles one person to obtain from the Court a remedy against another person.

The first principle is that once a cause of action has been held to exist or not to exist, that outcome may not be challenged by either party in subsequent proceedings. Fourth, there is the principle that even where the cause of action is not the same in the later action as it was in the earlier one, some issue which is necessarily common to both was decided on the earlier occasion and is binding on the parties: Duchess of Kingston's Case (1776) 20 St Tr 355.

If this were a matter governed by the common law I would hold that a cause of action ought not to be held to accrue until either the injured person has discovered the injury or it would be possible for him to discover it if he took such steps as were reasonable in the circumstances.

If in litigation upon one such cause of action any of such separate issues as to whether a particular condition has been fulfilled is determined by a Court of competent jurisdiction, either upon evidence or upon admission by a party to the litigation, neither party can, in subsequent litigation between one another upon any cause of action which depends upon the fulfilment of the identical condition, assert that the condition was fulfilled if the Court has in the first litigation determined that it was not, or deny that it was fulfilled if the Court in the first litigation determined that it was.