Bundy then increased his exposure to £11,000 after the assistant manager of Lloyds failed to notify him of the company's true financial condition.

Denning held that the contract was voidable owing to the unequal bargaining position in which Bundy had found himself vis-à-vis the bank.

He held that undue influence was a category of a wider class where the balance of power between the parties was such as to merit the interference of the court.

[1] Denning began by stating that the general rule is that a person who signs a contract must fulfill its terms.

By virtue of it, the English law gives relief to one who, without independent advice, enters into a contract upon terms which are very unfair or transfers property for a consideration which is grossly inadequate, when his bargaining power is grievously impaired by reason of his own needs or desires, or by his own ignorance or infirmity, coupled with undue influences or pressures brought to bear on him by or for the benefit of the other.

He noted the bank's concession that "in the normal course of transactions by which a customer guarantees a third party's obligations, the relationship does not arise".

Instead, the bank loans officer gave his own views on the son's business and advised Bundy to give the guarantee.

That was a manifest breach of the duty to take fiduciary care: "then any possible use of the relevant influence is, irrespective of the intentions of the person possessing it, regarded in relation to the transaction under consideration as an abuse – unless and until the duty of fiduciary care has been shown to be fulfilled or the transaction is shown to be truly for the benefit of the person influenced ».