Issue estoppel
An estoppel of record that arises where a particular issue that was judicially determined in previous litigation between the parties has been raised again under a different cause of action. Issue estoppel dictates that the legal issues which overlap will be treated as having been decided already. Issue estoppel is part of the broad legal principle of res judicata (claim preclusion – i.e. matters already decided cannot be brought up again).
Issue estoppel applies to legal issues, not facts, and does not apply in criminal law. Issue estoppel only applies after a final judgment based on the merits of the case by a court with jurisdiction. Issue estoppel is not completely absolute – in some cases, courts may refuse to enforce it if an injustice would result.
The case law authority for the existence of issue estoppel is Blair v Curran [1939].