ABSTRACT
Duress is essentially a common law concept. Alongside it must be placed the equitable doctrine of ‘undue influence’. This operates to release parties from contracts that they have entered into,1 not as a result of improper threats, but as a result of being ‘influenced’ by the other party, whether intentionally or not.2 The precise scope of the concept may be due for reconsideration. At present there are authorities which are treated as being concerned with undue influence, largely because of the limited scope given to duress at the time they were decided. In Williams v Bayley,3 for example, the plaintiff had agreed to give a mortgage over his colliery as security for debts incurred by his son, who had forged his father’s signature on promissory notes. The creditors had threatened that the son would be prosecuted if the mortgage was not given.4 The agreement was set aside as being obtained by undue influence. Similarly, in Mutual Finance Ltd v John Wetton & Sons Ltd5 implied, though not explicit, threats to prosecute a member of a family company in relation to a forged guarantee, led to the company giving a new guarantee.6 This was again set aside on the basis of undue influence. Both these cases involve ‘pressure’ being placed on a party in much the same way as occurs with duress. It is possible that the expansion in the type of threats which are now treated as potentially giving rise to duress7 would mean that they would now be put in that category. There is still the difficulty, however, that the courts seem reluctant to extend duress to implied rather than explicit threats. There is a strong argument that all these situations, involving pressure resulting from express or implied threats, might be usefully re-categorised as ‘duress’, leaving ‘undue influence’ to deal with relationships where one party has lost autonomy because of their relationship with the ‘influencer’.8 At the moment the courts have not been prepared to take such a step.
