What is cause of action estoppel?

Cause of action estoppel is grounded in the judicial intolerance of litigation by instalment and the ancient prohibition against a party splitting its case. It incorporates what is often referred to as the “might and ought” principle meaning that a defendant must bring forward every defence based on the subject matter at one time, once and for all. This longstanding rule derives from the reasons for judgment of Wigram V.C. in the seminal case of Henderson v. Henderson, [1843-60] All E.R. Rep. 378 and is often abbreviated as the “Henderson Rule”. Its application compels conformity to the principle that there is only one opportunity to prosecute a claim or raise a defence, unless special circumstances exist.