The issue here is whether the variation of the contract is valid. Generally, if the contract itself clearly allows for the variation, the variation will be binding. However, if the contract does not clearly provide for variations, for the variation to be valid, both parties must agree to the changes and the following must be present.
EITHER Fresh consideration
If there is fresh consideration for the change or variation, the change or variation will be valid. This means that both parties get something in return for agreeing to the change.
OR Seal or deed
If the variation is made by way of seal or deed, there is no further requirement that there must be fresh consideration and so the variation will be legally enforceable.
OR Williams v Roffey Exception
The exception was established in the case of Williams v Roffey where the defendant sub-contracted carpentry works to the plaintiff. But after some time, the plaintiff honestly could not go ahead, as he was in financial difficulties. The defendants promised the plaintiff extra amounts if the work was completed on time, as if there was a delay, the defendants would be liable to the owners of the flats under their contract with the owners. However, not all extra payments were made and so the plaintiff sued the defendants and the court upheld the claim. Hence it would appear that if changes are made to the contract without dishonesty or fraud, and the party being sued has got a practical benefit or avoided a disbenefit, the changes may be upheld.
OR Promissory estoppel
If a contracting party has made a clear and unambiguous promise to change a term in the contract and the other party has relied on the promise, and the court is of the view that it is very unfair or inequitable in the circumstances for the party making the promise to go back on his promise, he may be stopped from going back on his promise even if there is no fresh consideration. (High trees case)
Misrepresentation
The