Port of Melbourne Authority v Anshun Pty Ltd
High Court of Australia · 1981
Port of Melbourne Authority v Anshun Pty Ltd (1981) 147 CLR 589
A party lost, then sued on a point it could have run the first time. Is there a rule against saving your best argument for later?
What happened?
A workman was injured when steel girders being handled by a crane struck him. He sued both the Port of Melbourne Authority and Anshun, and damages were apportioned between them. The Authority and Anshun had a contract containing an indemnity clause, but neither raised it in that proceeding. The Authority then began a second action against Anshun, relying on the indemnity to recover what it had paid.
What did the Court decide?
The second action was barred. The indemnity was so closely connected with the subject matter of the first proceeding that it should have been raised there, and the Authority was estopped from relying on it now.
Proposition
What is the principle?
A party may be estopped from raising in later proceedings a matter that was not litigated earlier, where the matter was so relevant to the subject of the first proceeding that it was unreasonable not to have raised it then.
Why does this case matter?
It is the reason Australian pleadings are drafted defensively, and the reason advice on a first proceeding routinely canvasses claims nobody intends to run. In practice the case appears far more often as a warning in a letter of advice than as a decided point in court.
The name has become a verb — practitioners speak of an argument being "Anshun estopped" — which tells you how routine the reasoning has become. Note what it is not: although its application turns on an evaluation of the circumstances, it operates as a rule of law rather than as part of the court's discretionary control of abuse of process. Keeping those two apart matters, because the arguments available under each are different.
Exam and application relevance
Ask what the first proceeding was actually about, then ask whether the new matter belonged to that subject. Unreasonableness is judged in the circumstances as they stood then — the expense of running the point, whether the facts were known, whether the issues were genuinely suited to being tried together. Bringing separate proceedings can be perfectly reasonable, and showing that a point could have been raised earlier establishes nothing on its own.
Check your understanding
The indemnity claim was never argued or decided in the first proceeding. Why was the Authority nonetheless prevented from running it?