Where a party promises to 'give releases' from guarantees but cannot formally do so (only the bank can), discharging the underlying guaranteed indebtedness provides the substantive equivalent of a release and constitutes sufficient consideration. Alternatively, practical benefit to the promisee or detriment to the promisor from discharging the debt suffices as consideration, following Williams v Roffey Bros and Musumeci v Winadell.
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