Ps sued D (their employer) for failing to tell them about changes to their dept. pension plan of which they would have been able to take advantage, had D told them about it earlier (there was a time limitation which had passed on taking advantage of the new benefit). HL held that it was an implied term of the contract of employment that D would tell P about changes to the pension plan.
Lord Bridge: The law will imply a duty on D to inform P in the following circumstances: Where (1) the terms are not negotiated by the employee but by a representative body or by reference; (2) a term in the contract makes a valuable right available to the employee, contingent upon his action; (3) the employee “cannot, in all the circumstances, reasonably be expected to be aware of the term unless it is drawn to his attention”. This is on the basis that the parties intended P to be able to take advantage of the term, else why create it?