In order to establish whether the undertaking to pay
the additional £50,000 to Simpsons is actionable, we need to consider if all the elements of contract between
Moe and Simpsons are present. There seems to be no uncertainty as to the offer
and acceptance, the terms of contract are clear and unambiguous. In accordance
with Edwards v Skyways/Esso Petroleum
v Customs and Excise Commissioners, intention to create legal relations
can be presumed between the parties acting in course of business. The legal
issue of valid consideration should be
given more attention as Moe has promised to pay extra £50,000 to Simpsons to
complete the work which had already been paid under the original contract  and was due to be performed no later than 30
September 2017 at a price of £500,000.

The case of Currie
v Misa provides that a valuable consideration, in the sense of the law,
may consist either in some right, interest, profit, or benefit accruing to the
one party, or some forbearance, detriment, loss, or responsibility, given,
suffered, or undertaken by the other. In Dunlop
Pheumatic Tyre v Selfridge consideration is defined as “…. an act or
forbearance of one party, or the promise thereof is the price for which the
promise of the other is bought.”

The promise made by Moe can be actionable if it
satisfies the principles of consideration.

In this case, the act did not precede the promise (Re McArdle), consideration moves
from the promisee where Moe promises to pay Simpsons extra £50,000 for completion
of the previously agreed work (Tweddle
v Atkinson). From cases Mountford
v Scott and Thomas v Thomas
we know that consideration must be sufficient (but not necessarily adequate) and
of some economic value (Chappell v
Nestle).  There is
a problem with sufficiency of consideration in this case as the performance of
an existing duty owed to the same promisor cannot amount to good consideration under
Stilk v Myrick. One may argue though, that Simpsons have provided
valuable consideration in support of Moe’s promise by exceeding their existing
contractual obligations subcontracting a specialist water filtration company to
supply and install the new specialist filtration system to meet more rigorous
health standards (Hartley v Ponsonby)
and thus completing construction of the brewery in time.

We can also take into account the case of Williams v Roffey which established
that, in the absence of duress, performance of an existing contractual
obligation owed to the same promisor can provide valid consideration if a
practical benefit (or a practical avoidance of disbenefit) is thereby conferred
upon the promisor.

Pursuant to the Glidwell criteria from Williams v Roffey, Simpsons entered
into a contract with Moe to do the construction work in return for £500,000 and
prior to completing the works, Simpsons approached Moe with the newly made
discovery of water pollution by a nearby nuclear power station which would
delay building for indefinite period of time, and so clearly notifying Moe that
Simpsons will not be able to complete the works by the agreed date. Moe then
promised £50,000 in addition to the original price in return for Simpsons’s
promise to subcontract a specialist company which was vital for accomplishing the
works on time. There is nothing in the facts to infer that Moe’s promise was
induced by duress or fraud by Simpsons, which in its turn would indicate that presumption
in Stilk v Myrick cannot be rebutted.
The water supply was indeed polluted and
this factor was known at the time when contract was formed. Moe not only received a benefit of more expensive specialist filtration
system but also has benefited from being able to use the initially intended water
supply which has ultimate significance for the brewery, as well as from the
work being completed on time, and avoided the disbenefit of finding the
alternative water supplies. Based on the above and taking into account the lack
of fraud or duress, Simpsons may rely on Hartley
v Ponsonby and also rely on the exception provided by Williams v Roffey and Moe will have
to make payment of extra £50,000.