What is presumed undue Influence under English contract law?

Under English contract law, presumed undue influence refers to a legal principle which presumes that a relationship of trust and confidence exists between certain individuals, such as a solicitor and client, parent and child, or doctor and patient. In these relationships, one party is in a position of power or influence over the other, and it is presumed that the stronger party has used that influence to obtain an unfair advantage in a contract. When undue influence is presumed, the onus is on the stronger party to prove that the contract was entered into freely and voluntarily, without any coercion or pressure. If the stronger party is unable to rebut this presumption, the contract may be set aside on the basis of undue influence. In summary, presumed undue influence is a legal principle in English contract law that presumes that a relationship of trust and confidence creates a situation where the stronger party has used their position of power or influence to obtain an unfair advantage in a contract. The onus is on the stronger party to prove that the contract was entered into freely and voluntarily.