Mr. and Mrs. Lee provide a guarantee to a bank over a loan for a motor vehicle purchased by their son Lim. Lim subsequently defaults on his repayments and the bank seeks to enforce the guarantee against his parents. At the time the guarantee was entered into, neither parent had a good grasp of the English language, both were elderly and they received no independent legal advice. Mr. and Mrs. Lee believed that the extent of their liability was far more limited than it was. Upon what grounds could it be argued that reality of consent is missing from the guarantee agreement? What would be the likely status of the agreement?