Laches is an equitable defence arguing that a claimant has delayed unreasonably in enforcing a right and that this delay makes it unjust to grant the remedy sought. In practice, it allows a defendant to resist equitable relief (such as an injunction, specific performance or rescission) where the claimant’s undue delay has caused prejudice or changed circumstances.Laches is developed and explained primarily through case law rather than statute. Courts typically consider (1) the length of the delay, (2) the reasons for it, and (3) whether the defendant or third parties have suffered detriment, for example through reliance, loss of evidence, or altered position.In England and Wales and Northern Ireland, laches operates within the wider law of equity alongside statutory limitation periods; it may bar equitable relief even where a claim is issued within the limitation period. In Ireland, the doctrine is similarly recognised in equitable proceedings, particularly in property, trust, and contract disputes. Scotland does not use the terminology of laches, but analogous concepts exist through mora, taciturnity and acquiescence, which can bar claims where there has been unreasonable delay and apparent acceptance of the status quo.