I think it is likely that on this point the law in the U.S. and U.K. is probably similar since the concept of duress comes from the common law, though I will not guarantee the U.K is the same. In the U.S. duress refers to the use of some kind physical force, theat of physical force, or other illegal acts or threats to compel someone to do something, such as signing a contract for example. The classic example of duress is putting a gun to the person’s head and telling him to sign the document or he’ll be shot. The use of legal pressure is not duress. Thus, generally speaking, the threat by an employer that an employee will be fired if he does not sign something would not be duress since for the most part a threat to fire an employee is perfectly legal. In that circumstance, while the employee might well fear loss of his job and feel compelled to sign to avoid getting fired, it is still not duress.

