Contracts are based on the enforceable agreement of the parties, that is, they are based on consent. However, there are occasions where that consent was not freely given and, in such cases, English contract law has evolved a number of mechanisms that vitiate the contract on the basis that one party's consent was impacted by the other party.' Discuss the elements that are said to vitiate consent so as to provide possible relief to the innocent party. With reference to UK CONTRACT AND CASE LAW, please provide further references to cases etc.