circumstances which are not likely to persist, promissory estoppel can be used to extinguish legal rights. This final limitation to the scope of estoppel operates in the sense that the doctrine applies to representations relating to past and present events only by excluding the future events executory promise. However, promissory estoppel may permanently extinguish the rights of the promisor to claim lump sum after part-payment. In D & C Builders Ltd v Rees, Lord Denning expressed that the: To conclude, the above limitations help to clearly outline its parameters. This essay has defined with the use of cases to demonstrate the successful attempts to depart from the traditional approach set by the Hughes and the High Trees cases. The parameters of this doctrine seem presently not to be clearly defined. These consequences have caused the parameters of promissory estoppel to be no longer an established and well-settled area, which may interpret a huge problem to the development of contract law. The threats to the limitations of promissory estoppel, manifested from the continuing evolution of promissory estoppel, may pose turbulence in contract law and open the flood gate to litigation. Therefore, the application of the modern promissory estoppel replaces the traditional limitations set in the landmark cases. This equitable doctrine which originally acts as an exception to the doctrine of accord and satisfaction with subject to limitations now appears as an open and unlimited doctrine. Other estoppels Contractual estoppel The law relating to contractual estoppel was summarised in Peekay Intermark Ltd v Australia and New Zealand Banking Group Ltd: Issue estoppel The civil law use of issue estoppel or res judicata (literally translated as "the fact has been decided") is relatively uncontroversial. It expresses a general public interest that the same issue should not be litigated more than once even when the parties are different. The criminal law application, called double jeopardy provides that a person should not be tried twice for the same offence. A notable case occurred in relation to the Birmingham Six where the House of Lords ruled in Hunter v Chief Constable of the West Midlands Police that issue estoppel applied when the Six sued West Midlands Police for damages for assault. However, in their earlier criminal trial they had claimed to have been assaulted to gain confessions, and that court had rejected the allegation of assault. Lord Diplock said: Other estoppels Estoppel in pais (literally “by