When an action is brought to annul a proceeding, the defendant cannot plead such proceeding in bar.

Explanation

(English-origin maxim.) When a suit is brought to annul a proceeding, the defendant cannot use that very proceeding as a bar to the action — the matter in dispute cannot serve as its own defense.

Where this applies

• A homeowner sues to annul a fraudulent foreclosure, and the bank cannot use the foreclosure itself as a defense to block the lawsuit.
• A party sues to void a contract obtained by duress, and the other side cannot point to the same contract as a bar to the suit.
• A citizen challenges the validity of an administrative order, and the agency cannot use that very order as grounds to dismiss the challenge.