Does promissory estoppel extinguish the contract right under English law?

No, promissory estoppel does not extinguish contract rights under English law. Promissory estoppel is a doctrine in English contract law that allows a party to enforce a promise made by another party, even if the promise does not meet all the requirements of a formal contract. The doctrine operates as a defense against the enforcement of a contract in certain circumstances, but it does not extinguish the underlying contract rights. Instead, it acts as a means of enforcing a promise where a formal contract would otherwise be unenforceable, or where it would be unjust for the promisor to rely on the formal contract in the circumstances. The doctrine of promissory estoppel operates in conjunction with the contract rights and is not a substitute for the underlying contract.