 Undue influence in English law

Undue influence in English law is a field of contract law and property law whereby a transaction may be set aside if it was procured by the influence exerted by one person on another, such that the transaction cannot "fairly be treated the expression of [that person's] free will".Historically the doctrine had predominantly been invoked where the person who is exercising undue influence over another person either enters into a contract with the affected person or receives a gift from them.