''McDonald v Attorney-General'' is a cited case in New Zealand regarding satisfying the requirement in

promissory estoppel A promise is a commitment by someone to do or not do something. As a noun ''promise'' means a declaration assuring that one will or will not do something. As a verb it means to commit oneself by a promise to do or give. It can also mean a capacity ...

for reliance by the other party.

Background

McDonald was a Southland

wheat Wheat is a grass widely cultivated for its seed, a cereal grain that is a worldwide staple food. The many species of wheat together make up the genus ''Triticum'' ; the most widely grown is common wheat (''T. aestivum''). The archaeologi ...

farmer. The Wheat Board had advised wheat growers that wheat grown that had a baking score of 12 or higher would be purchased by the Board, and that such graded wheat could only be sold to the Board. In knowledge of all this McDonald expected the Board to purchase his wheat. However, due to an outbreak of wheat mould in

Southland Southland may refer to: Places Canada * Dunbar–Southlands, Vancouver, British Columbia New Zealand * Southland Region, a region of New Zealand * Southland County, a former New Zealand county * Southland District, part of the wider Southland Re ...

, the board found it had little demand for such wheat, and as a consequence, the Board refused to purchase his wheat. McDonald eventually sold his wheat to other parties, at a loss, and he sued the Board for compensation.

Held

The court ruled that promissory estoppel applied here, and awarded McDonald compensation, effectively turning promissory estoppel from a shield, into a sword. Holland J stated "''In converting promissory estoppel from a "shield" to a "sword" care must be taken not to extend it further into a weapon of the nature of an atomic bomb that will destroy the existing framework of legal principle by way of provision for compensation in the fields of both contract and tort''"

References

Court of Appeal of New Zealand cases New Zealand contract case law 1991 in New Zealand law 1991 in case law {{NewZealand-case-law-stub