united-kingdom
Does promissory estoppel or estoppel by convention apply to this situation?
<p>Suppose party A has some legal right L. A and party B are in negotiations. B wants to do an action, C, which would entail some risk of loss, but if B is successful, both A and B will acquire a benefit (A will acquire this benefit through its legal right, L). A says they do not want C to happen, since they consider C to be unjust. B does C nonetheless, and is successful. Is A now estopped from enforcing L?</p>

<p>What more detail would you need to decide whether or not estoppel can be established against A?</p>

<p>[Edit: one further detail. The benefit would have to be shared between A and B, so A claiming some benefit reduces B's benefit]</p>

<p>For promissory estoppel to be relevant B would need to demonstrate that it decided to do action C <em>because</em> of some representation by A that they would not enforce L. Absent the representation or if B would have done C anyway, A is not estopped.</p>
