The cases show that equity has been more successful than the common law in the enforcement of a waiver or promise of forbearance. In Birmingham and District Land Co v London & North Western Railway (1888) 40 Ch D 268, Bowen LJ, explained the position as follows:

If persons who have contractual rights against others induce by their conduct those against whom they have such rights to believe that such rights will either not be enforced or will be kept in suspense or abeyance for some particular time, those persons will not be allowed by a court of equity to enforce the rights until such time has elapsed, without at all events placing the parties in the same position as they were in before.