This became known as the doctrine of promissory estoppel. It began in
High Trees with Lord Denning (when he was a fairly new but perceptive
and innovative judge) using his powers of equity to provide a suitable
remedy where there was a need, and has developed since into a fully
recognised doctrine. It is an example of an inspired opportunity to develop
the law as a way of mitigating unfairness, as the original rule in Pinnel’s
Case (confirmed in Foakes v Beer) that part payment of a debt cannot
discharge liability for the whole debt, can be very harsh in certain
circumstances if strictly applied. Authority for Denning’s proposal was
found to some extent in the following House of Lords case.
Some important points concerning promissory estoppel:
1 In Hughes the rights of the landlord had been suspended, but High Trees
took this a step further in saying that the right to rent for the 1940–45
period had been extinguished, since it would be inequitable ever to revive
it, as the money could never be recovered.
2 Promissory estoppel can only be used as a defence, and not to bring a new
cause of action where none already existed. In Combe v Combe (1951) a
husband promised to pay his wife £100 per year on separation, and when
he defaulted she sued him for ten years’ payments, claiming to rely on
High Trees. It was held that the doctrine could not be used to start a cause
of action, where no consideration existed. It was a ‘shield and not a sword’.
3 A promisor can withdraw his promise when he gives reasonable notice
that he is doing so, provided that the promisee is able to resume his
60 Contract law
Hughes v Metropolitan Railway Co (1877)
Under a repairing lease the tenants of a property were ordered to make
repairs or be evicted, and were given a period of six months to do this.
However, negotiations then began for the purchase of the property, but
these came to nothing, so the owners sued immediately for possession.
The tenants claimed that while the negotiations for purchase were
taking place the notice to repair was suspended, then giving them time
to make the repairs. The court agreed that the obligations to repair were
suspended during this time.
Lord Cairns made a statement to the effect that in the tradition of
equity, if parties are in a contractual relationship, and one promises to
excuse the other from strict legal duties, ‘the person who otherwise
might have enforced those rights will not be allowed to enforce them
where it would be inequitable having regard to the dealings which have
thus taken place between the parties’.