Ratio Decidendi
Where a party enters a contract partly because of duress to the person and partly for other reasons, the contract is voidable for duress. The victim need not prove that duress was the sole or predominant reason; it is sufficient that it was a reason. The burden shifts to the party exerting duress to show it had no effect.
Facts
Armstrong, the chairman of a company, made death threats against Barton, the managing director, to pressure him into purchasing Armstrong's shares on favourable terms. Barton entered the agreement partly because of the threats and partly because he believed the deal was commercially acceptable.
Judgment Summary
The Privy Council held the agreement was voidable for duress. Even though Barton had commercial reasons for the deal, the threats were a contributing factor. The burden was on Armstrong to prove the threats played no part in Barton's decision.
Key Quotes
"If Armstrong's threats were 'a' reason for Barton's executing the deed he is entitled to relief even though he might well have entered into the contract if Armstrong had uttered no threats."
— Lord Cross
Subsequent Treatment
Applied in cases of duress to the person. For economic duress, the test is narrower (DSND Subsea v Petroleum Geo-Services [2000]).